Time zone awareness

[lemonyte]

The server should be aware that the time zone of all dates and times it deals with are in either Pacific Standard Time or Pacific Daylight Time, depending on the time of year. This should make it behave consistently regardless of the time zone in the location where it is deployed. Currently, the server treats all date and time objects as naive and local, so it will likely behave differently if deployed on a server configured in UTC, for instance.