Calendars
Hijri and Gregorian dates: keep the calendar convention
Understand calendar conversion, civil Hijri versus an authoritative calendar, and why a converted record should keep its original date.
ToolRoof Library
Understand the idea. Put it to work.
Calendars
Calendar conversion: eras, leap months and week-years
Read dates in context: distinguish an era, an inserted month and an ISO week-year before comparing records from different calendars.
How we prepare articles
We develop original explanations and examples with automated assistance, then check calculations and factual claims against the cited sources. ToolRoof is an editorial credit, not a claim of expert review or personal advice. We correct verified errors and change update dates only for substantive revisions.
Contact