This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.
set method is used to change the system time.
Note: To change the timezone of the system, it's required to use the Settings API.
- The new time to set. It can be either a Date object or a number. If a number is provided, it represents the number of millisconds since midnight UTC January 1, 1970.
Not part of any specification.