Best time to take GMAT?

Hello. I’m a first-year FLDP associate in an F100 company. Humble brag: I’m a total idiot but a really good test-taker (I got a 1590 SAT and used to tutor people in HS for test taking strats). I’m looking to take the GMAT next year to attend b-school for an MBA. I’m not really picky (would like to get into a T10 school but would honestly vibe with any school I can get into). I’ve had a pretty busy workload this first year and wanted to know when is the best time to take the GMAT? I’m in a 2 year program w/ 6 month rotations. Should I take the GMAT after I graduate the program? It seems like GMAT should been taken during a time w/ a light load. Also, is it ever too early to take the exam? I want to ensure I have enough time to practice.