Timezone overlap
In short
Timezone overlap is the number of hours in a day when your working hours and a remote team's working hours coincide, used to check whether real-time collaboration is practical.
A remote job posting often states a required overlap, such as '4 hours with US Pacific time'. Indonesia (WIB/UTC+7) overlaps only a few hours with US teams but overlaps well with Australia, most of Asia, and parts of Europe. Async work reduces how much overlap is needed, but some live meetings or pairing sessions usually still require a minimum window.