The ascendant (lagna) moves through all twelve signs in a day, so it changes roughly every two hours. The houses, and which planet rules which area of life, are set by it.
What a few minutes can change
Near the edge of a sign, a difference of ten minutes can move the ascendant, and with it the timing of planetary periods.
If you are unsure of your time
- Check a hospital record or a family horoscope.
- Give the closest window you know (for example, "early morning, before 7").
- Tick "I don't know the exact time" while booking; Archit will work with what you have and tell you how confident the reading can be.