There is an unofficial reminder bot on the Fediverse. It can remind you minutes, hours, days, weeks, months or years later. To use it, just mention the bot in a post or reply and include the period you want to be reminded after. For example:
@ remindme @ mstdn.social 1 week
To be reminded in a DM, include the word "dm" in small letters:
@ remindme @ mstdn.social dm 1 week
(Remove spaces in the address to make it work, I've only included spaces to avoid setting off the bot!)
