Daily Stand-ups are effective when all the team members come together to share their impediments and see if they are aligned towards the sprint goal. Pick a time that works convenient for the team members that work in different geographical locations.

Simple: Choose a democratic time that allows everyone to participate. If this is not possible, record the daily meeting so those who are absent can watch it at a convenient time.

In general, stand-up refers to everyone huddling and calling out their wins, plans and impediments, if any. So, the options we have exercised over time are: - The team chooses a common time across all geographies. - Have a stand-up per geography and post updates on a common channel with exquisite call outs, either the same person conducting them or different as per geographies. None the less, having a summary published anyway post any call keeps everyone informed and targeted.