What timezone does Authority relays use?

Question

This is the header file retrieved from http://86.59.21.38/tor/status-vote/current/consensus/

network-status-version 3
vote-status consensus
consensus-method 26
valid-after 2017-09-16 18:00:00
fresh-until 2017-09-16 19:00:00
valid-until 2017-09-16 21:00:00

I want to know what is Time zone of these timestamps Are these UTC or any other timezone?

Answer 1

The timezone is UTC.

Almost all network services will use UTC for any time values used in the protocol. It's the industry standard.

From dir-spec.txt:

3.4. Exchanging votes

   Authorities divide time into Intervals.  Authority administrators SHOULD
   try to all pick the same interval length, and SHOULD pick intervals that
   are commonly used divisions of time (e.g., 5 minutes, 15 minutes, 30
   minutes, 60 minutes, 90 minutes).  Voting intervals SHOULD be chosen to
   divide evenly into a 24-hour day.

   Authorities SHOULD act according to interval and delays in the
   latest consensus.  Lacking a latest consensus, they SHOULD default to a
   30-minute Interval, a 5 minute VotingDelay, and a 5 minute DistDelay.

   Authorities MUST take pains to ensure that their clocks remain accurate
   within a few seconds.  (Running NTP is usually sufficient.)

   The first voting period of each day begins at 00:00 (midnight) UTC.  If
   the last period of the day would be truncated by one-half or more, it is
   merged with the second-to-last period.