Is it possible to determine when an Aspect starts and ends?

[jeferson-sb]

I'm working on implementing a Transits chart and I need to list aspects for planets in a particular day.
I'm able to determine the aspect between two bodies with swe_calc_ut successfully but I cannot estimate how long that aspect will occur, like

Sun opposition Mars  ✔️
Duration: 3 days ❓

I was playing around with the planet transit longitude towards the aspect degree but I could not find any consistent result.
I'm not an astrology expert so I would like so guidance in that!
Thanks

Related to #51

[jeferson-sb]

bump