Converting Timezones on the Command Line

Convert from a foreign zone to the local zone

This functionality is built-in in the date command. If the local timezone is CET and you have an appointment with someone in England (GMT):

$ date -d '2020-01-16 14:00 GMT'
Thu 16 Jan 2020 03:00:00 PM CET

Convert from the local timezone to a foreign one

If the local timezone is CET and you want to convert to EST, use a environment variable to set the foreign timezone as local for the time the command runs and apply the same trick as above:

$ TZ=EST date -d '2020-01-16 15:00 CET'
Thu 16 Jan 2020 9:00:00 PM EST

Timezone info

Run tzselect to find the timezone for a country.

Check Wikipedia to get more details: https://en.wikipedia.org/wiki/List_of_tz_database_time_zones

Sources