Sending date and time from android to arduino?

Projects Programming
1

I'm currently working on a project, home automation with scheduling, using uno,HC-05,relays and DS3231.
i can send and receive data from android and arduino, but i have no idea how to send time and date to arduino using our app.

-what data type should i use to send time and date to arduino?
-how to compare time and date now to sent variable from android?

2

I'd use Unix Time as it makes comparisons between two times very straight forward.