I have user's timezone, let say
timeZone: 'America/New_York'
I want to perform some tasks at midnight according to the user's timezone. How can I check if the midnight has arrived in this timezone?
Last midnight in a specific timezone:
new Date(new Date().toLocaleDateString('en-US', { timeZone: 'America/New_York', timeZoneName: 'short' } ))
Database friendly UTC time of last midnight in a specific timezone
new Date(new Date().toLocaleDateString('en-US', { timeZone: 'America/New_York', timeZoneName: 'short' } )).toISOString()
Note: understand 'last midnight' as today-in-zone midnight
Explanation:
new Date() is current time (whatever the zone - time object)
.toLocaleDateString('en-US', { timeZone: 'America/New_York', timeZoneName: 'short' } ) displays the current date (no time, so midnight) in the specified zone (string of time with zone ref)
new Date(<above midnight time in zone>) parse the midnight time in zone and display corresponding current timezone time (time object)
.toISOString() display above at UTC reference (ISO datetime string)