I would try it after 6-12 months, but before that use it as primary for 3 months, then have a balance around 15% of the total limit at the time you're ready to pull the trigger.
Good luck.
Ive had 2 cards. Combined the 2nd one below with the first. Heavy usage and asked on 60,90, and 120 days. Was pretty succesful each time. But Missy can be finicky at times. Date her a lot. And she'll reward you. Favorite color of roses is red. 
I'm with @AverageJoesCredit -- I don't think there is any best time. I know I had no luck--they always denied my CLI requests with reasons like not using enough of my credit line--and then one day, boom! I got one! LITERALLY nothing had changed as far as usage goes. I had been using it regularly, specifically because I wanted to improve my chances of a CLI, but it hadn't mattered. Then, with just usual spending, it got approved. *shrug* My utilization never went above 8%-9%, both before and when I got the approval.
To add i havent seen any cli since , and a little before , Covid began. They took away my bts as well. Granted usage has been really low except one month but i keep periodically smashing the button. Never know. Only thing i can think of as a risk is maybe they decide to 4506 me or something but as much as i luv Miss Disco, ive been getting my groove on with Navy so im ok if i lose her affections
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@AverageJoesCredit wrote:To add i havent seen any cli since , and a little before , Covid began. They took away my bts as well. Granted usage has been really low except one month but i keep periodically smashing the button. Never know. Only thing i can think of as a risk is maybe they decide to 4506 me or something but as much as i luv Miss Disco, ive been getting my groove on with Navy so im ok if i lose her affections
This must be a person-by-person thing. I've gotten both a CLI and multiple BT offers during the pandemic. Keep smashing that love button! One day, like magic, you're going to get some love! I did.....FINALLY.