Homebrew 3DS RTC Help

[dalekman9999]

Hi all, I went to change my Raw RTC for the first time, noticed something strange, that the date was listed in like 2001/02/28
Is that normal for it to be so far back? And would editing it forward that far to the current actual date be an issue at all. Thanks!

 

[MegaBoyEXE]

Yes, it's normal.
The default RTC date is 2000-01-01 12:00 AM
When the 3DS leaves the factory, the RTC chip has the default date set, and starts running from there.
The date and time that you set in the Settings app is actually an offset from the RTC. This way games can detect whenever the clock was changed by doing a system call.
By changing the raw RTC value, there's no way games can detect as it is a hardware data. Just set both raw RTC data to current date and time, and also adjust the OS current date and time to fix the offset value. Whenever you want to adjust clock to DST for example, just change the raw RTC clock without any game penalties!

One thing I'm not sure is that I have read one time (I think it was in 3DBrew, altough I couldn't find the information anymore) is that the raw RTC value for the year goes from 2000 to 2050, which means that setting it to 2017 you are lowering it's working range. But GodMod9 allows setting it from 2000 to 2099, so I can't confirm if this information is true or not.