rncbc.org a.k.a. Rui Nuno Capela

I think you're referring to meter or time signature of the session (song). In that case you can look into File/Properties... as for the current session properties.

You can set the "Beats per Bar" value which corresponds to the numerator (upper number) of the time signature. Default is the popular 4/4 ;) Please note that you have access to this value only (beats or quarter-notes per measure). As for the denominator (the lower number) there's no real need to make it any more specific. For just that I believe you can have get away with the "Snap per Beat" feature when placing or lengthning your notes ;)

HTH
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rncbc aka Rui Nuno Capela