Inside is a third box, labeled DO NOT OPEN UNLESS YOU ARE IN THE TIME ZONE WHERE YOU OPENED BOTH PREVIOUS BOXES.

xkcd

Time Capsule Instructions

In the aviation world, they don't use AM/PM times. Instead, all times are assumed to be AM unless they're labeled NOTAM.

xkcd

METAR

No, of course we don't microwave the mug WITH the teabag in it. We microwave the teabag separately.

xkcd

Making Tea