You till, add compost, fertilize, water as needed and you plant. Sometimes everything comes up, sometimes nothing.
Indeed you are right. My date for spring planting is May 5 for the warm weather plants like corn beans etc. Of course if it happens to be a snow storm that day, I am not going to plant. If it is a nice day I likely will if nothing else is of higher priority.
Some years all comes up nicely, other years not much comes and I must replant. When I get failure, it is usually because of inclement and cool weather. The seeds lie in the ground and rot. Does the moon have a bearing on all of this? I don't know. Frankly, I ignore the moon in my garden planning. I have had enough great successes over the years, that I am convinced one can have a great garden with never a second thought about the moon.
Just looking at some plantings this year and putting the moon in the picture:
This year I planted corn May 5 (dark moon) May 17 (1st Quarter moon) June 16 (first quarter moon) All did very well.
Potatoes April 27 (full moon) Have done well.
Onions March 19 (first quarter) have done excellent.
Spinach March 17 (new moon) Most came, but it could have been better. The snow just left the ground on the 15th. The soil was cold.
I planted some beets and cabbage April 27 ( Full Moon) that failed. We were having a long cold wet spell.
OK, that was fun, but still don't know what effect, if any, the moon had on my successes or failures.