I would like to run cron jobs when it is 7AM locally in Western US, Eastern US and some other timezones in Asia and Europe.
This is a node.js server, so I can probably use node-cron to do this but I'd like to use the regular cron if it's at all possible.
Times in the crontab always refer to the current system time. You will have to subtract or add timezone differences to calculate the execution intervals on your server.
E.g.:
Your server is in the Western US (UTC+8) and the system date is set to be UTC+8. 7am can be specified in crontab using
0 7 * * * /run/me-for-western-us
To run a script when it is 7 am in Eastern US (UTC+5), you need to subtract 3 hours
0 4 * * * /run/me-for-eastern-us
Do the same for all other timezones.