Schedule start and end times incorrect migrating from 1.6 to 1.7
Description
Existing installations upgrading to 1.7 from 1.6 may find that:
Schedules don't display correctly; and
when editing the Schedule from Administration|Organisation it has Start Time and End Time fields like: 365337:00
The Start Time and End Time properties are stored in the database as date/times and must be relative to 1970-1-1.
Existing installations may have later dates. These can be corrected manually, or by running the following script:
Environment
None
