What is the maximum value of the time interval?

hello, everyone
first, i'm not good at english. Sorry about that

I want to know maximum value of time interval
I need one or half hour interval
can i use this interval like picture?

Yes, you can use one hour (3600000) or an half hour (1800000).

Will your app stay open that long ?

yes i will

Is the app just for you? If not, how do you know that your users are leaving the app open for so long? If the app is in the background, the timer slowly freezes in backgroud / idle mode (on Android > 5 due to Doze mode).

The theoretical maximum for the Interval property is 2^31-1, so roughly 2 billion milliseconds in the future (about 24 days and change). However, as others have pointed out above there are a number of practical considerations that may limit the upper bound further.