[ska]

> Would people find it acceptable if you painted for an hour and charged for 15 hours?

It is perfectly common (and reasonable) to be expected to be compensated something for being available outside your normal hours.

E.g. many plumbers will charge you extra (or build into their fees) for a sunday emergency call, why shouldn't a developer ?

If I were in that consultants shoes I probably wouldn't propose 16 hours, but for sure I would bump my hourly rate (say 1.5x) or a min charge of 4 hours or something, if you wanted me available on say an hours notice over the weekend. If you wanted me available at the drop of a hat it would be more.

Scheduling normal work over weekends, etc. is a different issue, but being "on call" should always involve some compensation for the impact on your life.