Conditions will dictate, your location weather, wet or dry field etc. Typically, here, you try and set up for nice weather, and it does happen, maybe not at the right time, but you will get it sooner or later. So you cut, and I am not sure what you are cutting it with and what kind of hay grasses or what you are actually cutting, that changes things.
Nice dry air breeze, in the upper 70's 80's you could cut one day, moderate cutting with a mower conditioner, disc mower and the next morning, ted it, orchard grass lets say, and similar, it should be dry enough for raking into windrows, which you do mid afternoon, when ever it makes sense if not let it stay spread out another day, more you do that the more it sun bleaches but that is how it goes. Next day, rake into windrows, and immediately bale, problems I have seen is moisture on the bottom of the windrows, so leave it over night, you may have to rake or turn it over to dry the bottom, ground moisture etc. We have made bales a little loose at times, but through a thrower you can only go so far with that and from field to field if cut at the same time things change.
So once you cut, then ted, at the right time, do what Bruce said, at that time if its crisp, and snaps off etc, should be ok to rake and bale.
So many variables, if you use a sickle, no crimping action, those stalks may not dry as fast, so you may leave in the swath longer, then ted or something that works, I have not cut hay with a straight up sickle in a long time, we had a side sickle on the tractor too, all orchard grass, thick, moist ground, took longer than it did with a mower conditioner, that is for sure.
I have never seen hay grasses cut then immediately wind-rowed, for dry grass hay, nor afalfa, or any for that matter, maybe hayledge or something we don't do here or I just don't know a darned thing about LOL !!! Well they do that for sileage, dairy farmers do that and chop it, so yes there is that, and its common still, my friend would hire his sileage body truck out right after planting was done.
Its nice to get the top side dry, whether you ted or not, we used to let the swath stay until it was right, then turn it with a side delivery rake one time, let that dry, so that would have to be done mid morning, then that afternoon, you still have enough time to bale before the dew becomes a problem.
Its interesting all the variables, and what people do to get it done. Leafy crops will lose leaves, and feed value if too dry and raked, tedded or otherwise handled more to dry it out, so there is that scenario, plus thick 2nd cuttings, and even first in moisture laden fields where you get good weather after lots of rain, all of that can be a pain to dry if the weather does not cooperate, then try oats cut for the grass or similar grain crops for hay, thick stalks, just loaded with moisture. Sometimes everything lines up, we just had a great window of weather, if you could not dry that hay then, no matter what you had, there was something wrong, was around the solstice, no humidity, low 80's as a high, breeze, like today, and once you figure what is ideal methods to dry what you have specifically, that usually won't change, just the weather will, every time LOL ! Humidity, temperature, and of course if you do get rain on it, usually better in the swath, seems to shed it off, only bleaches part of it if not a real soaker, then you dry and its still decent feed value, seen that enough, its great when the weather is perfect, and you can cut all of it, and have enough time to bale and put it all away, rare but has happened, we did 60 acres like that in '07, got it all in just before the rain came on July 4th.
There are moisture meters too, but we've done it by hand to see, never had one of those.
