My tank is five months old: I waited 4-weeks before putting in 2 clowns and with a cadence of 3-4 weeks, I'm now up to 7 fish, 17 corals and a constantly-redecorating pistol shrimp.
Initially, I changed the same amount weekly and about 2x that monthly, but now my frequency is goal-based.
My corals are so small that they're not drawing calcium or magnesium at a higher rate than what the water change replenishes (same goes for my itty bitty spots of coraline), and my alkalinity is stable, so I'm really just focusing on Nitrates/Phosphates.
My water changes are also on a rate basis as opposed to volume. For example, if my nitrates increased to 20, but I wanted them at 15, I would want to do a 25% water change. I could try to swing this in a day, but given the number of buckets I have, I might spread this evenly over three days and target a 30% because on each subsequent day, you're swapping a higher ratio of water you just added.
In 2023, I'll probably get back to a fixed change on a fixed schedule, but it'll still be set by the NO3/PO4 levels I want to maintain. So the key for me, more than consistent water changes is consistent testing!
Hope this helps.