It's a date time in epoch format: number of ms since reference date 1970-01-01T00:00:00.000Z. The type is an alias to avoid further explanation for each variable.
1970-01-01T00:00:00.000Z
It's a date time in epoch format: number of ms since reference date
1970-01-01T00:00:00.000Z
. The type is an alias to avoid further explanation for each variable.