Pokémon Crystal days of week bug on flashcart

[dysphoria]

>inb4 get a another flashcart

Hellow.

I'm using an Everdrive GB clone simply called "Game Flash GB." As expected, it doesn’t support RTC features, pretty obvious.

Thing is, when playing Pokémon Crystal or any Gen 2 game, the day of the week cycles way too fast. I expected the time on that game would be frozen (like in repros). I found the RTC patch that lets you set the clock manually, but it only affects the hour and minutes, the day still loops uncontrollably.

Is there any mod or patch that can force the day of the week to stop? Or any other fix? I know there are some events in the game depending on the day and I'm worried I could get softlocked during gameplay.

By the way, the clone has a CR1220 battery, but I don’t think that's related to RTC. Honestly, Im not even sure what that battery is for, since the game appears to save using SRAM.

 

[VinsCool]

Just wondering, did you try to use it without the battery, or with a new battery to see if the same behaviour occurs?

I seem to remember the days of the week and time going all over the place on original hardware was a side effect of a battery almost dead, so this may be related?

 

[Ryccardo]

Is there any mod or patch that can force the day of the week to stop? Or any other fix?

Looks like bad implementation of the MBC3 mapper... so...
Real fix? Get another flashcard (though it's rather hard to recommend one)
Workaround? There's a well written disassembly of Crystal so it's plausible to develop a mod that makes the clock settable every time you load (this is in fact in the official game if the MBC3 reports no power to run the clock, or if the day counter runs out after not playing for a few years) and having the time off software interrupts; I don't know if anyone has already done this, though...

I know there are some events in the game depending on the day and I'm worried I could get softlocked during gameplay.

If it really is RUNNING no problem with that, though it might reduce your enjoyment
Even then they're all optional (the boat schedule is the big one but there's an exception on your first trip IIRC, and you can probably get the train ticket in 2 hours if you know what you're doing but take your time)

By the way, the clone has a CR1220 battery, but I don’t think that's related to RTC. Honestly, Im not even sure what that battery is for, since the game appears to save using SRAM.

The SRAM , which needs external power in case you turn off the console without using the reset button (assuming you can press it at all with your console)!

 

[VinsCool]

Workaround? There's a well written disassembly of Crystal so it's plausible to develop a mod that makes the clock settable every time you load

This might be the best solution, I know plenty of ROMhacks actually allow changing the clock at any time specifically for that reason.

 

[dysphoria]

This might be the best solution, I know plenty of ROMhacks actually allow changing the clock at any time specifically for that reason.

There's a patch, but it only allows me to change the hour, not the weekdays. Those automatically loops very fast.

Looks like bad implementation of the MBC3 mapper... so...

Now that you mention it, I checked a list of MBC3 games that use a calendar, Another one is... an Mary and Ashley Olsen agenda. Huh.

Aanyway, that game also lets you set up a calendar. It also goes really crazy, and reaches the end of the calendar in just a few seconds. The clock never moves. I'm assuming the game seems to be adding like 60 days per second, which is probably the same thing in Pokémon as well.

 

[ChronoCrossfangirl2002]

There's a patch, but it only allows me to change the hour, not the weekdays. Those automatically loops very fast.

Now that you mention it, I checked a list of MBC3 games that use a calendar, Another one is... an Mary and Ashley Olsen agenda. Huh.

Aanyway, that game also lets you set up a calendar. It also goes really crazy, and reaches the end of the calendar in just a few seconds. The clock never moves. I'm assuming the game seems to be adding like 60 days per second, which is probably the same thing in Pokémon as well.

in conjunction with that patch, couldn't you hypothetically save in front (or at least near) an RTC event (I.e National parks gate for bug catching contest) then use crystal's unused RTC editor via:

• hold the Down, Select, and B buttons simultaneously.
• Release and hold: While still holding Select, release the Down and B buttons.
• Hold and release: Still holding Select, press and hold the Up and Left buttons.
• Let go of Select: Release the Select button.

all on the title screen. while tedious, it's really the only thing i can suggest for a cart like that as i unfortunately own the same one.

edit: my bad you did mention it adds like 60 days per seconds, that'd be playing a very stubborn slot machine atp

 

[dysphoria]

It's not a clock issue, I can set hours and minutes just fine. The real problem is with the day of the week, that part cycles completely out of control. I checked other events in the game like rival rematching on Mondays, and seems to be that the days are looping in parallel.

 

[ChronoCrossfangirl2002]

It's not a clock issue, I can set hours and minutes just fine. The real problem is with the day of the week, that part cycles completely out of control. I checked other events in the game like rival rematching on Mondays, and seems to be that the days are looping in parallel.

View attachment 509994

yes i'm aware however what i suggested also let's the player set the day of the week as well, though i wasn't sure if that would fix it but it's worth a shot

 

[squall1989]

There's a patch, but it only allows me to change the hour, not the weekdays. Those automatically loops very fast.

Now that you mention it, I checked a list of MBC3 games that use a calendar, Another one is... an Mary and Ashley Olsen agenda. Huh.

Aanyway, that game also lets you set up a calendar. It also goes really crazy, and reaches the end of the calendar in just a few seconds. The clock never moves. I'm assuming the game seems to be adding like 60 days per second, which is probably the same thing in Pokémon as well.

well this seem to be some problem with the flashcart for sure. I used the patch to play just about 1 week ago, you can cycle through day of the week just fine, simple move clock past 11:59pm friday to 0:00 am of saturday, all event happen right away without need to do anything else

Post automatically merged: Jun 30, 2025

just incase, maybe you can send me the rom that you before and after you apply the path in DM, maybe in a miracle it's the rom's problem

 

[SooraMaru]

>inb4 consigue otro flashcart

Helado.

Estoy usando un clon de Everdrive GB llamado simplemente "Game Flash GB" Como era de esperar, no admite funciones RTC, lo cual es bastante obvio.

El problema es que, cuando juegas Pokémon Crystal o cualquier juego de la Generación 2, el día de la semana transcurre demasiado rápido. Esperaba que el tiempo en ese juego se congelara (como en las repeticiones). Encontré el parche RTC que te permite configurar el reloj manualmente, pero solo afecta la hora y los minutos, el día todavía se repite sin control.

¿Existe algún mod o parche que pueda obligar a que se detenga el día de la semana? ¿O alguna otra solución? Sé que hay algunos eventos en el juego dependiendo del día y me preocupa que pueda quedar bloqueado suavemente durante el juego.

Por cierto, el clon tiene una batería CR1220, pero no creo que eso esté relacionado con RTC. Honestamente, ni siquiera estoy seguro de para qué sirve esa batería, ya que el juego parece guardarse usando SRAM.
[ADJUNTAR]509933[/ADJUNTAR]
[ADJUNTAR=completo]509999[/ADJUNTAR]

I thought it was my flashcard but I have the same problem, and even the patches out there don't work for me.

 

[Peeteris]

Yes, I have the same problem with the same flashcard. Was surprised that there's not much info about that on the net.

 

[tan-tan]

Can confirm this is an issue for games that use MBC3 on this card. Be aware that this extends further than just the clock in Gold/Silver/Crystal, your Pokemon boxes from 8 onwards will experience corruption, likely data being written somewhere it isn't intended.

 

[Dirtbag_Jim]

[EDIT: added IPS patch files + bug highlighted by @SooraMaru ]

Think I have an easy fix for this issue.

Was having the same issue and it was honestly really bugging me. This RTC Day progression issue on my EDGB clone seems to be present only on my GBC, not on my GBP. Obviously though, not being able to play Gen 2 Pokemon on a GBC is not ideal (especially since I know a lot of people get Gameboy's to pretty much only play Pokemon).

I'd read about people changing ROM mapper types in order to flash them to different single game flash carts, and based off what @tan-tan mentioned about this being a problem specific to MBC3 games on this type of card I think I managed to find an easy fix.

I used the GB ROM analyzer tool from romhacking to change my ROM's mapper from MBC3 to MBC5, and this appears to have fixed this issue for me on my everdrive clone.

I applied this fix to a Pokemon Silver ROM which I'd already applied an RTC patch to (the one that lets you change the time from the PokeGear, so same as @dysphoria uses), and so far it works perfect for me. The game no longer has the problem where the day progresses at an absurd rate, and instead now acts like a standard non-RTC repro pokemon cart ROM (i.e. the time+day don't advance at all, since MBC5 doesn't support RTC), and I'm able to just change the time from the pokegear whenever is needed. MBC5 supports SRAM + Battery, and it's the same mapper type used for official Pokemon Yellow ROM's (non-JP), so saves work as usual with this fix.

I've created IPS patches for Crystal, Gold, and Silver (English versions) to attach to this post. These IPS patches include the mapper fix, RTC changer (change time from pokegear), and general bugfixes (from ROMHacking.net). Just apply it to a stock Gen 2 Pokemon English ROM. I can't confirm if my personal patch files work for other language ROMs, so there are instructions below on how to do this patch manually. If I have time again in the future I will try to make IPS patches for the other language ROMs (e.g. Spanish, German, etc) and add them to this post.

!!IMPORTANT!!
Based on feedback from Sooramaru, there is a bug present where the day will change when you change pages on the Pokegear. The only current fix is to manually change the day/time when needed from the Pokegear using the RTC patch which allows changing time. This is neccesary anyways considering the lack of RTC on these carts, but it is worth noting.

I know these flashcarts are very popular due to their price, and Pokemon Gen 2 is obviously extremely popular too, so hopefully this helps everyone in this thread, and anyone who stumbles upon it.

This is my first post here, so hopefully it doesn't break any rules. After lurking without an account for ages I figured this was a good chance to finally contribute to the community.

NOTE: I made a save with my patched ROM, and tested it on a stock ROM and it loads up just fine, so if you do ever encounter major issues down the road, you should be able to return to using a stock ROM and you won't lose your progress on your save file. Please make backups though if possible, just in case, as I take no liability for potentially corrupt saves and there is always a chance something could go wrong (as evidenced by me missing the Pokegear bug until SooraMaru pointed it out). I'm only human and simply don't have the time or motivation to be able to thoroughly 100% complete playtest all Gen 2 Pokemon games with this patch + constantly cross-check compatibility of saves with the stock ROMs.

_________________________________________________________________________________________

For anyone who wants to do their own ROM patching, here are the instructions:

It is highly reccomended to apply an RTC patch to your ROM before applying the solution outlined below. You would need to do this anyways for the RTC functions in these games (as these carts have no RTC), but there is also a bug present where the day will change when you change pages on the Pokegear, so you will need to use an RTC patch to fine tune the day for the few time based events in the game which depend on specific days of the week. I advise using the RTC patches which allow you to change time from the Pokegear, rather than the patch which gets you to set the time upon each boot, so that you can change days on the fly whenever is neccesary.

I'm a new user and this is my first post, so I can't post links, but go to romhacking(.)net and search for the relevant RTC patch for your Pokemon game to use before applying this fix. Also on romhacking, go to utilities and search for, and download, 'Game Boy ROM Analyzer / Header Editor / Checksum Fixer Incl Source', it's the program I used for this fix.

Steps:
1. Open the ROM file you want to patch in the "Game Boy Rom Analyzer" program
2. Under "Cartridge Type" change it to 'ROM+MBC5+RAM+BATTERY'
3. Use the "Write ROM" function (found under 'Edit')
4. Then use the "Fix Header Checksum" function (also found under 'Edit')
5. Finally, use the "Write ROM" function again to save the changes to the ROM file.
6. Put the patched ROM on your EDGB clone and enjoy (hopefully)!


_________________________________________________________________________________________


IGNORE (Just putting key terms here so it's easier to find when searching): Gameboy Game Boy Color Pokemon everdrive clone EDGB flashcart flash cart multicart multi cart day RTC real time clock fast problem bug glitch fix patch

 

[dysphoria]

Think I have an easy fix for this issue.

Was having the same issue and it was honestly really bugging me. This RTC Day progression issue on my EDGB clone seems to be present only on my GBC, not on my GBP. Obviously though, not being able to play Gen 2 Pokemon on a GBC is not ideal (especially since I know a lot of people get Gameboy's to pretty much only play Pokemon).

I'd read about people changing ROM mapper types in order to flash them to different single game flash carts, and based off what @tan-tan mentioned about this being a problem specific to MBC3 games on this type of card I think I managed to find an easy fix.

I used the GB ROM analyzer tool from romhacking to change my ROM's mapper from MBC3 to MBC5, and this appears to have fixed this issue for me on my everdrive clone.

I applied this fix to a Pokemon Silver ROM which I'd already applied an RTC patch to (the one that lets you change the time from the PokeGear, so same as @dysphoria uses), and so far it works perfect for me. The game no longer has the problem where the day progresses at an absurd rate, and instead now acts like a standard non-RTC repro pokemon cart ROM (i.e. the time+day don't advance at all, since MBC5 doesn't support RTC), and I'm able to just change the time from the pokegear whenever is needed. I highly recommend applying an RTC patch to your Pokemon Gen 2 game before using this fix, unless you don't care about any of the RTC functions in the game. MBC5 supports SRAM + Battery, and it's the same mapper type used for official Pokemon Yellow ROM's (non-JP), so saves work as usual with this fix.

I'm a new user and this is my first post, so I can't post links, but go to romhacking(.)net and search for the relevant RTC patch for your Pokemon game to use before applying this fix. Also on romhacking, go to utilities and search for, and download, 'Game Boy ROM Analyzer / Header Editor / Checksum Fixer Incl Source', it's the program I used for this fix.

Steps:
1. Open the ROM file you want to patch in the "Game Boy Rom Analyzer" program
2. Under "Cartridge Type" change it to 'ROM+MBC5+RAM+BATTERY'
3. Use the "Write ROM" function (found under 'Edit')
4. Then use the "Fix Header Checksum" function (also found under 'Edit')
5. Finally, use the "Write ROM" function again to save the changes to the ROM file.
6. Put the patched ROM on your EDGB clone and enjoy (hopefully)!

I know these flashcarts are very popular due to their price, and Pokemon Gen 2 is obviously extremely popular too, so hopefully this helps everyone in this thread, and anyone who stumbles upon it.

This is my first post here, so hopefully it doesn't break any rules. After lurking without an account for ages I figured this was a good chance to finally contribute to the community.
_________________________________________________________________________________________

NOTE: Afaik there shouldn't be any problems with changing the game mapper to MBC5 (please correct me if I'm wrong). Regardless, I made a save with my patched ROM, and tested it on a stock ROM and it loads up just fine, so if you do ever encounter major issues down the road, you can rest easy knowing you can return to using a stock ROM and you won't lose your progress on your save file.

NOTE 2: If I eventually make enough posts to be allowed to post links, I'll edit this post to include direct links to the RTC patches and the ROM Analayzer program to make it easier for people to find the neccesary tools/files.

IGNORE (Just putting key terms here so it's easier to find when searching): Gameboy Game Boy Color Pokemon everdrive clone EDGB flashcart flash cart multicart multi cart day RTC real time clock fast problem bug glitch fix patch

Thank you, it worked! I also suspected that was something related to the mapper. As EDGB has some kind of custom mapper option, I tried to boot the rom changing the mapper from ROM to MCB5, but nothing really happened when changed.

I'm curious if this also works on other MBC3 games like that Olsen twin's agenda, but I'll try later since they're not that important. I'll make my own set of Pokémon roms, but I think I can't upload directly them to the forum, so I'll upload them somewhere else.

 

[dysphoria]

Hey, I made an interesting discovery, I don't know how I didn't notice before.

While I was trying to record some footage for a video tutorial, I found out that the bug isn't present on Super Game Boy. So tried to boot the game on other models (Pocket, Advance and SP) and the weekdays didn't cycle way too fast as in Color.

So I don't know, maybe it's something related to the GBC's hardware itself and how it handles the ROM mappers. In any case, it's already solved by @Dirtbag_Jim by changing the mapper to MCB5 in conjuction with the RTC patch, so no need to look further on this, I think.

 

[SooraMaru]

I also noticed that when you turn the page on the PokéGear, the days advance one by one, but without affecting the time (it remains static).

 

[Dirtbag_Jim]

Thanks for the feedback guys!

@dysphoria thanks for testing out this issue on multiple gameboys! It's really helpful, I currently only have a GBP and GBC on hand and couldn't do more comparisons. I'm definitely interested in why this seems to only affect GBC's.

@SooraMaru thank you so much for pointing that out! I can't believe I hadn't noticed that, I think I was so content just seeing the day not moving anymore upon first opening the pokegear that I kinda just tuned out about the issue and didn't pay enough attention afterward.

I just tested on my GBC and can confirm I have that same issue with the day progressing when changing screens on the pokegear. Unfortunately I do not currently have a fix for this. I've just tried out all the other mapper types compatible with these carts, and tested the ROMs on my GBC, and they either don't work at all (MBC1 & 2), have the nonstop extremely fast day progression (MBC3), or have the pokegear page change issue that you've brought up (MBC4 and 5). No other mappers are supported by these carts, so there's not really anything else that could be tried.

I'm honestly really stumped, and may just have to admit defeat here and accept the day progression with pokegear page change as a compromise I have to live with. In the grand scheme of things I think I'll be okay with this bug, as I can still fine tune the day for the time based events in the game by using the RTC patch. I know this probably isn't an acceptable compromise for everyone, so I'll edit a a disclaimer onto my original post just so that anyone who want's to use my patch solution can be aware of the issue, so thank you again SooraMaru for bringing up that issue! It genuinely was super helpful to know about

I really wish I could help further resolve this for everyone, but I unfortunately don't have the neccesary knowledge to really dive into the actual code of the games to see if I could resolve the issue on a deeper level (i.e. to create something like a romhack). Hopefully someone more knowledgeable than I am may one day have a proper solution for this.

Really sorry again for not noticing this bug earlier, and for not being able to further help everyone in resolving it properly. I hope the patch solution I came up with can still help those of us in the community who are on a tight budget to be able to enjoy Gen 2 Pokemon games, even if it's not perfect.

 

[ChronoCrossfangirl2002]

I also noticed that when you turn the page on the PokéGear, the days advance one by one, but without affecting the time (it remains static).
View attachment 527856

I can also confirm this as of testing on a Non SP GBA though when soft resetting the minute value goes up by 1 if enough time has passed for it to do so

 

[Dirtbag_Jim]

Think I may have somewhat of a guess at why this is an issue on GBC's and GBA's, and not the monochromatic models: I read that the GBC CPU runs at double speed mode compared to the GBP and DMG (and the GBA uses built in GBC hardware to play the games, so I'd assume it's the same).

I'd guess there's something wrong in the old spaghetti code of these clones (or in the hardware) that's causing it to misread whatever from the GBC hardware and misinterpret it as the clock signal.

Also I'm sorry to say guys but I think I may be calling it quits on this project. I just finished running a bunch of battery life tests on my gameboys, and I found that my EDGB clone only gives me 40% of the battery life of a stock/repro cart. I might just bite the bullet and nab an EZ Flash Jr or a legit Everdrive (if I'm patient enough to save and wait for the sale).

EDIT: I may still come back to this in the future if I've gained the necessary knowledge to attempt resolving this issue, coz honestly right now even without planning to retire my EDGB clone, I unfortunately just don't have the expertise to resolve this further. For now though, I hope my bandaid solution is still good enough for all of us on a budget, and hope you all have good luck with catching em all

 

[ChronoCrossfangirl2002]

Think I may have somewhat of a guess at why this is an issue on GBC's and GBA's, and not the monochromatic models: I read that the GBC CPU runs at double speed mode compared to the GBP and DMG (and the GBA uses built in GBC hardware to play the games, so I'd assume it's the same).

I'd guess there's something wrong in the old spaghetti code of these clones (or in the hardware) that's causing it to misread whatever from the GBC hardware and misinterpret it as the clock signal.

Also I'm sorry to say guys but I think I may be calling it quits on this project. I just finished running a bunch of battery life tests on my gameboys, and I found that my EDGB clone only gives me 40% of the battery life of a stock/repro cart. I might just bite the bullet and nab an EZ Flash Jr or a legit Everdrive (if I'm patient enough to save and wait for the sale).

EDIT: I may still come back to this in the future if I've gained the necessary knowledge to attempt resolving this issue, coz honestly right now even without planning to retire my EDGB clone, I unfortunately just don't have the expertise to resolve this further. For now though, I hope my bandaid solution is still good enough for all of us on a budget, and hope you all have good luck with catching em all

firstly i wanna say thank you for your work it's a genuine great step forward for what it does, if you ever plan on coming back to this whenever that maybe, I'd recommend asking around pokecommunity, you're likely to get the attention of someone like Rangi, or Piacarrot who seem to have a pretty big understanding of how these titles work considering both have history with binary and decomp projects.

though this just a suggestion, regardless thanks a bunch!