I'm doing a ritual an usually did it during the hour of the moon if I do it during another hour will that destroy my work
Oh and it's a 40day spell (not a magic square)
It won't ruin your work, but if you do it at the correct planetary hour it will have even more power.
The important thing is that you continue the work and complete it for as long as it takes, even if it takes more than just one 40-day set.
Even if it were a Square, doing it at a different hour once still doesn't ruin the work.
"Ideally, each day, the mantra chosen for the Moon should be recited during the hours of the Moon for that day. This is ideal, but regardless never skip any days, regardless of the hour"
However, since it is not a Square, the planetary hour does not have to be that rigid. But yes, coordinating with the correct time can also give a certain advantage. But it is not strictly necessary. I would also focus a lot on intention and concentration in your magical work, that is really necessary.
