How To Know The Duration Of A Song/Pattern?

is there any way to know the duration (in seconds, minutes or whatever) of a whole song or just a single pattern in Renoise?

Well, if you go to the first line of the second sequence position, you also have the complete playing time of the first pattern.
But only in seconds, not milliseconds. And also for the pattern of that size.
The timer on the right above shows the time of the actual position of your cursor.
If you want to know the playing time of different sizes, adjust the pattern size of your first programmed pattern in the sequencer.

unless you click on it, then it shows you the time left from the current cursor position to the end of the song ;)