今一時十五分です。

To express the time, use a number constructed with 時, the counter for hours, followed by a number constructed with 分, the counter for minutes.

十時十分です。
It’s ten past ten.

The question word for time is made by adding the counter 時 to the question prefix 何. You can make it clearer that you’re asking for the current time by putting 今 (“now”) at the start.

今何時ですか。
What time is it now?

We can also use a geographical location as the topic of the sentence.

イギリスは今何時ですか。
What time is it in the UK now?