One other option is to layover the aircraft while the crew acheive minimum rest. BA do this with Luanda.
I guess it would all depend on the circumstances and the airline concerned. Back in my charter days, I did plenty of week long trips due to the frequency. Other times, I have flown into a destination, such as Montego Bay, night stop, then private charter over to Cancun, nightstop, then operate back to the UK.