There are many variables when it comes to curing hay before baling. Temperature, wind, relative humidity, heaviness of the crop, whether you are tedding it or just raking. I've been doing hay for about 15 years and every year is a little different. I'm in Western Washington and if I have days in the upper 70's or higher I usually cut one day, ted the next day, rake into windrows the next day and bale the following day. Sometimes there are is a day between tedding and raking. I don't remember the ideal moisture content because if I grab a handful and it has the right crinkle sound then I know it's ready to bale. Here's a UMN extension link for more information:
Preserving the value of dry stored hay