exit status 1 'Time' does not name a type
You don't mention which library you are using (which library does #include &lt;DS3231.h&gt; refer to?)

The DS3231 library here https://github.com/NorthernWidget/DS3231 defines a DateTime object which appears to have similar elements to what you are trying to access in 't' (hour, min, sec etc).

I would try defining 't' as a DateTime object.