1. Create a new mission in editor, using any time setting
2. Start mission preview, and open debug console
3. Enter the following into a watch field: date
4. Enter the following into another watch field: dateToNumber date
5. Enter the following in the execute field: skipTime (365*24)
6. Observe date change (date goes backwards, by more than a year)
7. Repeat steps 4 and 5 a few times (date goes forward, sometimes by one year, sometimes more and sometimes less).
8. Enter the following in the execute field: skipTime (3*365*24)
9. Note game get stuck at about 1 FPS, hour of day reported by date command changes to impossible values, clouds may appear strange. Exit mission and editor, load any other mission and note performance is still terrible. Game may crash if left long enough.