I just happened to remember that my last Amex CLI was on June 30 because I started gardening on July 1. Of course, that didn't last long. So based on that it looks like I made my request at 189 days. I haven't really been counting days.
I don't even remember the exact date on my last Citi CLI, but I remember it was mid November, so I know to try again in late May. I don't care if I'm "late" by a week or so.
I really only keep up with CLI dates on Amex and Citi since my other issuers do HP on requested CLIs. They're supposed to be 6 months apart so it's not much to keep up with. Oh and Cap1 does SP CLIs, too, but that card is a permanent resident of the sock drawer so I don't really care to increase it and they probably won't give me anything anyway.
I kinda have a policy of not burning any HP on CLI. I'd rather save my HPs for products with earning features I don't already have and I can always move credit around if needed.
I've only done an HP for CLI twice. Once was for a CLI on my Citi DC as soon as I received it which I wish I hadn't done. They bumped me from $4500 to $6000 and the SP CLI page showed up on my account a few weeks later. I still had to wait 6 months, though, before they would give me another one. The other HP was for a CLI on my Synovus card which has no info online about CLI policies so I was flying blind on that one. They increased me from $1K to $9K so it was actually totally worth it, but I probably won't ask for any more from them.