Reminders
Ping yourself back later in the exact same chat (or DM) you asked from - a duration like 1h30m, or a clock time once you've set a timezone.
Setting a reminder
$remind <when> <message>
Also $remindme (alias), /remind. <when> is either a
duration - 1h30m, in 2 days, 30m - which always works no
matter what, or, once you've set one with $tz set <location>, a clock time like
3pm, tomorrow 9am, or monday at 6pm. Works in DMs too, not
just servers.
Without a saved timezone, a clock time like 3pm is rejected with a message pointing
you at $tz set <location> - stick to a plain duration if you'd rather not set
one.
Reminders must be at least 30 seconds out, and no more than 1 year. You can have up to 25 pending at once.
Delivery
When it's due, Pixie posts an embed with your reminder text in the exact channel (or DM) you set it from, pinging you if it was set in a server. If that channel's gone or Pixie can no longer post there, it DMs you instead as a fallback rather than losing the reminder silently.
Viewing your reminders
$reminders
Also /reminders. Lists your pending reminders (up to 25), each with an id and a relative "in X" time.
Cancelling a reminder
$remindcancel <id>
Also /remindcancel. Give it the id shown in reminders' output. Only
cancels a reminder that's yours and still pending.