Halachic day and Onah
A civil date alone is not always sufficient for a Taharah calendar. The Hebrew date and the Onah - daytime or nighttime - can also be part of the calculation.
Daytime and nighttime Onah
The daytime Onah is associated with the period from sunrise to sunset, while the nighttime Onah begins at sunset and continues until sunrise. Events on the same civil date can therefore belong to different Onot or Hebrew dates.
When does the Hebrew date change?
The Hebrew date advances with the beginning of the Halachic night rather than at civil midnight. An event after sunset may therefore belong to the next Hebrew date.
Why are location and time zone needed?
Sunrise and sunset depend on location. TaharaSmart uses the stored location and time zone for calculation rather than assuming one clock time for every user.
What if information is missing?
When an essential time, location or Halachic time cannot be determined, the system does not guess the Onah and instead indicates that clarification is required.