Discussed with Jonathan and Junio regarding whether we should support
letting user specify timezone or restricted to UTC only. There was no
defnite conclusion. I think it's a good idea to start with this
implementation which might result in the change landing or e.g. a
documentation change.

The patch add checking for user.hideTimezone and change environment
variable TZ to UTC in the beginning of cmd_commit if it's true. As a
result, when calculating timezone offset in datestamp(date.c) would result in 0. 

Shengfa Lin (1):
  hideTimezone: add a user.hideTimezone config

 Documentation/config/user.txt   |  4 ++++
 builtin/commit.c                |  5 +++++
 t/t7527-commit-hide-timezone.sh | 37 +++++++++++++++++++++++++++++++++
 3 files changed, 46 insertions(+)
 create mode 100755 t/t7527-commit-hide-timezone.sh

-- 
2.28.0.709.gb0816b6eb0-goog