Warsaw is 4.75 hours behind Kathmandu
Best overlap: 12:45 PM to 6:45 PM in Kathmandu is 8:00 AM to 2:00 PM in Warsaw.
12:45 PM to 6:45 PM in Kathmandu is when Warsaw is also working, at 8:00 AM to 2:00 PM their time. With 6 hours in common, treat scheduling almost as if the two cities were in the same region. The window above shifts seasonally: Warsaw keeps daylight saving while Kathmandu ignores it.