See exactly what each result used.

Source hierarchy

Legislation and tax/immigration authority guidance come first. Government calculators and manuals provide examples. Blogs and competitor tools never authorize a production rule.

Rule changes

• Detect a primary-source change
• Create a pending version and source diff
• Human-review examples and boundary tests
• Activate with an effective date
• Recalculate affected ledgers and explain the change

Professional-review state

When home, family, work, treaty or status facts cannot be resolved deterministically, the result stops at the day count and explains what remains unresolved.

Reminder limits