I want to agree, but there are times when you have to ask for timezones, like when you want to collect and present data in discrete time units like days. If a user wants to know how many app installs they have per 'day', you have to know what time the time the day they care about begins and ends before you start dumping data into those time delineated buckets. It's not always the timezone their browser uses. Especially not with agencies that are providing these services for clients that are somewhere else.