comma

[tipu s]

On Sunday, when I got up at 7 o'clock, I found that no one was at home.
Are both the commas correct? Or only the second one will be used?

[albertino]

On Sunday, when I got up at 7 o'clock, I found that no one was at home.
Are both the commas correct?(Yes) Or only the second one will be used?

(Not a teacher)

By fronting the time element(On Sunday), it is usually for emphasis. If not, it should be placed in the proper order as this:
When I got up at 7 o'clock on Sunday, I found that no one was at home.
When the subordinate clause is put before the main clause, a comma is normally required.
When I got up at 7 o'clock on Sunday(subordinate clause), I found that no one was at home(main clause).
Otherwise, no comma is needed:
I found that no one was at home(main clause) when I got up at 7 o'clock on Sunday(subordinate clause).

[Raymott]

On Sunday, when I got up at 7 o'clock, I found that no one was at home.
Are both the commas correct? Or only the second one will be used?

albertino is right. But given that you've written what you have, yes, the commas are correct.