Warsaw is 6 hours behind Kuala Lumpur
Best overlap: 2:00 PM to 6:00 PM in Kuala Lumpur is 8:00 AM to 12:00 PM in Warsaw.
For a call that suits both sides, look at 2:00 PM to 6:00 PM in Kuala Lumpur / 8:00 AM to 12:00 PM in Warsaw. You share roughly 4 hours a day. That's enough for regular meetings, but treat the window as prime time and guard it. Finally, Warsaw observes daylight saving and Kuala Lumpur doesn't, so this window shifts by an hour for part of the year — recheck it each spring and autumn.