sketch_oct29c:17: error: no matching function for call to
'DS3231::DS3231(const uint8_t&, const uint8_t&)'
DS3231 rtc(SDA, SCL);
^
That syntax is found in the Rinky Dink Electronics library.
http://www.rinkydinkelectronics.com/library.php?id=73
That library does not use the standard i2c library (Wire.h).
I would recommend either the rtcLib.h which is available through the library manager or the Jack Christensen DS3232.h which works for the ds3231 and integrates well with the time library.