Display correct day of the week with negative UTC offset

A duplicate subtraction of the UTC offset and DST time caused the creation
of an incorrect timestamp. In return this caused us to go back too far and
therefore moved us back one day.
Merge pull request #116 from marc1706/calendar/one_day_off

Display correct day of the week with negative UTC offset
[ticket/120] Move birthday block HTML to template files

B3P-120
Merge pull request #132 from marc1706/ticket/120

[ticket/120] Move birthday block HTML to template files