Probably timeElapsed/period.
So you’d maybe do one of the following:
Var timer=0
Start of layout
— enable sine
— set timer to 0
Every tick
— add dt to timer
— set text to timer/period & “ cycles”
var startTime=0
Start of layout
— enable sine
— set startTime to time
Ever tick
— set text to (time-startTime)/period &” cycles”