In the late 60s Skyways had 5 or 6 748s each summer, often leasing in for the period. One did daily shuttles Lympne to Beauvais, managing six round trips. A second also ran the route, doubling the schedule, on peak days with another six round trips; Fridays and Sundays were the peak days.
A third did the longer haul runs from Lympne; the route through Clermont Fernand to Montpelier and back took all day, and in the evening supplemented Beauvais and could do an intervening trip from there to East Midlands and back, all these three ending up back at Lympne close to, or after, midnight, which meant the coach got passengers to London Victoria around 2am, which in that era must have been pretty inconvenient for those on a budget, where night-rate black cabs were the only onward option.
A fourth aircraft did the inclusive tour hops from Lympne across the Channel, to Beauvais again or Ostend. One, sometimes two, aircraft spare or on maintenance. Probably no crews got weekend days off in the summer.