Get the current time in a form that looks like a Javascript timestamp.

Javascript timestamps are based on the venerable UNIX time_t data type, and show the number of milliseconds since 1970-01-01 00:00:00 UTC.

This expression gets the current time as a Javascript timestamp integer. (It does so correctly regardless of the current time_zone setting.)

ROUND(UNIX_TIMESTAMP(NOW(3)) * 1000.0, 0)

If you have TIMESTAMP values stored in a column, you can retrieve them as integer Javascript timestamps using the UNIX_TIMESTAMP() function.

SELECT ROUND(UNIX_TIMESTAMP(column) * 1000.0, 0)

If your column contains DATETIME columns and you retrieve them as Javascript timestamps, those timestamps will be offset by the time zone offset of the time zone they’re stored in.