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Year-Beginning Comparison

Historical year-beginning comparison

Compare how the same Gregorian day would be labeled in jurisdictions that used September 1, March 25, March 1, or January 1 civil year openings.

This page shows the Gregorian reference first and JDN second. JDN remains the stable shared day count behind all of these labels, so jurisdictions can still be compared without losing the exact underlying day.

Year-beginning rules in this comparison

These are the civic-year rules currently represented in the comparison set below.

Comparison results

Each row resolves the same Gregorian input against a different jurisdiction so you can compare both the local label and the year-opening rule side by side.

Jurisdiction Gregorian reference JDN Year rule Local civil label Style and regime Notes