The 2018-02-28 23:30 and 23:02 log entries are correctly considered
UTC by the JS code.
Yet, H2 month title uses local timezone, not UTC one. This triggers
a split of the title according browser local timezones:
- for local timezones in UTC or UTC-n, the correct month February is printed
- for local timezones in UTC+n, the +n 'March' is used instead.
This change fixes this bug asking the month in the UTC timezone.