If you open old occult books, you will find loads of timetables.
The saying “A time for each thing, for each thing its time” I believe stems from here.
You don’t just have “thursdays are for luck spells, fridays for love spells”. They go much more into detail.

They work like this: from bigger to smaller.
So you have the season first.
Then the phase of the moon.
Then the day (as above).
Then, of course considering from sunrise to sunset, the hours.

Which means that, according to old occult books, maybe that love spell you’ve just read, should be performed on a spring full moon, friday, in the hours of Jupiter.

While I’m so much happier with the approach that neopaganism has brought to this matter (either: do it when you have the time, or adjust your spell to the timing), this “old fashion” of doing things has its appeal.

Let’s say you want to do a big spell, a lifechanging one, something more than the usual daily glamour or little luck spells.
You select your spell, you select your day and everything else.

You look for that on your calendar… it’s five months away.
Oh. You say.
Well, let’s see the bright side.

You have five months to start collecting the supplies (the perfect ones, not just those that “will make do”).
You have five months to start acting accordingly.
Let’s say you want to do a job spell, or a home spell, or a travel spell.
Start taking courses, applying to anything, looking for places to live, making lists of what you want, saving even those little cents you can by chosing a cheaper product over another one.
And so on, and so forth.

All this will build up determination, focus, willpower, momentum.
To the summa of your spell.

Hope this helps 🙂