How is timestamp generated in android app?

Question

Android

Hello!
There is one social network, I have captured the traffic and am trying to repeat the request. But the problem is that you need to pass the Date parameter, it comes in the UNIX Timestamp format (example 1522775648232).
So, if you repeat the request without changing the data, even with the old Timestamp, then the server responds. The same combination, but with a different Timestamp and the server does not respond.
When I try to change the request, substitute another user ID for example, then the server does not respond either.
Thus, I came to the conclusion that the matter is in this Date parameter.
The software to which I send requests can substitute the current Timestamp, but it still does not fit.
Please tell me how I should generate this Timestamp so that the requests go through. Or does it not work as well as I think?
Thank you in advance.

Answer 1

So, if you repeat the request without changing the data, even with the old Timestamp, then the server responds. The same combination, but with a different Timestamp and the server does not respond.
When I try to change the request, substitute another user ID for example, then the server does not respond either.
Thus, I came to the conclusion that the matter is in this Date parameter.

I would come to the conclusion that the request has a checksum or some other way to check the integrity.