Kathmandu is 4.75 hours ahead of Vienna
Best overlap: 8:00 AM to 2:00 PM in Vienna is 12:45 PM to 6:45 PM in Kathmandu.
Your shared working hours run 8:00 AM to 2:00 PM in Vienna (12:45 PM to 6:45 PM in Kathmandu). The 4.75-hour gap barely gets in the way — you've got 6 hours of overlap, so pick whatever time fits the agenda. Just remember Vienna changes its clocks for daylight saving and Kathmandu doesn't, so confirm the overlap whenever the seasons turn.