How does localization affect when daytime cancellations are visible?

Question

Facebook posts announcements / reminders for events related to a particular day, such as birthdays. Does localization reflect when they are visible?

For example, if my birthday is February 1, will there be an ad in each other time zone starting February 1, local time, in my time zone or in some other time zone (for example, Greenwich Mean Time)?

Any option has disadvantages:

• If the announcements are based on local time, a friend who lives in India can see the announcement on the morning of February 1 for him, but I will receive him on the evening of the previous day. Or, if they live in Japan, they may not see him until the evening of February 1, when February 2 is already for me.

• If the announcements are based on my local time, then a friend may be confused when my birthday is actually, as the announcement will appear for them at least on another day.

_{For a birthday announcement, these are not very serious problems; this is just a simple example to clarify the issue}

Answer 1

I think the question largely describes a dilemma that does not have a good universal selection. For an example of a birthday, the problem is the vague definition of "birthday"; this is a social convention more than anything else.

If you think of something more objective as a “one-day offer” by a company, then it becomes even more obvious that the decisive problem is how things are defined. In a global review, the company must determine when the offer is valid (for example, on a specific day in a specific time zone) and report it accordingly.

The task of programming is to do this correctly. Basically, it is about creating time references relative to a specific time zone or time zone of users. Usually they require different approaches: server and client side. (The server’s time zone may not coincide with the specified time zone, but they must have a certain relationship.)