How do i get the time to apoapsis with vizzy?

Im makng a rocket that can get to a perfect orbit of 200km apoapsis and 200km periapsis with vissy. But theres a problem. I need to use vissy to get the time to apoapsis. For instance, once my craft finishes the initial orbit the apoapsis is usually somwhere in between 198 and 203km. With the periapsis being at around 120km. I want my code to go somehwrre along the lines of "if apoapsis>200000" set time mode timewarp 2, lock heading retrograde, wait until time to periapsis =< 5 seconds, set time mode normal, set throttle 0.2 wait until apoapsis=<200000, set throttle 0." Only thing is idk how to get the "wait until time to periapsis =< 5 seconds" part. Anyone know how or if its not possible an alternative way?