maps

calendar day streak with honest time zones

A streak counter with a two week calendar that groups absolute timestamps by their local date in the selected zone using Intl.DateTimeFormat instead of by elapsed hours, so switching zones really moves activities between days and splits or extends the streak. A slider walks the last activity from 23:30 to 00:30 around that zone's true midnight, computed by inverting the offset, while a panel explains which day it lands on, how long until it rolls over, and whether crossing midnight keeps, extends or breaks the streak.