One very important piece of advice - DON'T SKIMP ON SLEEP! Sleep is when memory consolidation happens, so if you're staying up late to study without sleeping, you won't hold onto those memories anyway, so it's wasted effort. Sleep deprivation can essentially cause amnesia in the long run, drastically hurting your score.

It's likely that you'll have to cut back a bit on socializing while you're studying. But don't think that you need marathon study sessions every day. If you can squeeze in 20 min here, 40 min there, you'll gradually build up a lot of content knowledge.

Don't try to do a 1-month intensive study period. If your work schedule is intense, you'll likely need 3-5 months to study for the GMAT, aiming for 1 hr a day on average.

Good luck!