More sensible repair time starts

[RHammond2]

It would be great if any operations at site wouldn't start until the next shift if less than an hour or two of work will be done on that task in the current shift.

Alternatively, it could make sense for shifts to be continuous with a rotating crew for x number of days until a vessel refresh is required, with a default of a single shift to maintain compatibility with land-based servicing regimes.