The best time to act is when the idea comes to you because if you wait, the idea is not going to go away,
But someone else might grab that idea out of the ethers where you found it in the first place and run it and you'd be standing there going, hey that was my idea.
No it was not. it was a gift to you from God/Universe that you did not accept.
Act when you're inspired.
Just take inspired actions. No hustle and grind required.