Hefsek Taharah
Hefsek Taharah is a central Halachic step before Shivah Nekiyim A digital calendar must distinguish between a day on which a Hefsek may be performed and a Hefsek that was actually performed and recorded
Eligibility for Hefsek Taharah counts the starting day as day 1 The fixed profile waits at least 5 days; custom settings allow a different waiting period Reaching eligibility does not record a completed check
Only a valid Hefsek Taharah report starts Shivah Nekiyim the next day A report on day 10 starts days 11–17 Without it, waiting continues even into the next month The next-day principle appears in Shulchan Aruch, Yoreh De’ah 196:1