I don’t think it means you work a full day, but that you bill a minimum of a full day for any weekend work.
A while back I worked at a consultancy that typically billed using a 15-minute granularity during standard office hours, reasonably rounded up/down. Unless otherwise contracted, outside of office hours the granularity increased to 1 hour rounded up. A 5 minute fix would be billed as an hour, a 65 minute fix as 2 hours, etc. It was also only undertaken for emergencies; general work requests would be done the next business day.
Generally all contracts were budgeted some number of hours per billing cycle per service. N full-time engineers would be converted to an equivalent amount of hours for the budget.
The result was that overtime was used judiciously and clients were rarely insisted on pushing big changes near the end of a day or on Fridays.
A while back I worked at a consultancy that typically billed using a 15-minute granularity during standard office hours, reasonably rounded up/down. Unless otherwise contracted, outside of office hours the granularity increased to 1 hour rounded up. A 5 minute fix would be billed as an hour, a 65 minute fix as 2 hours, etc. It was also only undertaken for emergencies; general work requests would be done the next business day.
Generally all contracts were budgeted some number of hours per billing cycle per service. N full-time engineers would be converted to an equivalent amount of hours for the budget.
The result was that overtime was used judiciously and clients were rarely insisted on pushing big changes near the end of a day or on Fridays.