alt Hacker NewsChildcare can be nice to have but it can also be a full-time job just getting the kids there if you have more than a few.
We certainly take advantage of things like free preschool; but if we look at it objectively (and ignore benefits to the child) it consumes more time than if we didn't use it - getting him ready, walking him to school, picking him up, etc. Since it's free, we look at "time spent" and it's something like 2-3 hours spent to "get" 3 hours.
Minus the commute you had to do most of that anyway though, right? We get my four year old ready and walk her to school (city free pre-k a few blocks away, plus paid aftercare).
It takes about an hour to get breakfasted, dressed, and ready which we would be doing anyway. Counting the walk both ways it's about 30 minutes of extra time for 8 hours of childcare.
Unless your commute is just huge I can't see that math being true.