Yep, this is the difference. By changing the 'Date Stamp' in Swapnote, you can send notes to up to a week in the future. By changing your 3DS date, you will simply send notes from that will appear to have the 'send date' from that time, but you will recieve them right away.Eh? But the time locked message you sent me to lynch Den was locked (I peeked by changing the date on my 3ds). I'm sure Mason's 2050 note was done by changing the date on the 3ds to 2050. At least, that was my impression.