How to Reproduce:
# set server timezone to `Americas/Chicago` (GMT-5)
# set user timezone to `Europe/Riga` (GMT+2)
# go to any trackable object (maniphest task or differential revision)
# press `Start Tracking Time` link
# submit the form
Then the error about incorrect time would be shown. Problem is that time in the error is 8h larger (timezone difference) larger than time what was entered by user.
{F1677555} {F1677557}
Version: https://secure.phabricator.com/w/changelog/2016.15/
P.S.
I know that bug reports on prototype applications are not accepted, but this should be an easy fix.