more comments

rickb777 · Nov 15, 2018 · 93168f6 · 93168f6
1 parent 9fcad74
commit 93168f6
Showing 1 changed file with 10 additions and 0 deletions.
diff --git a/gregorian/doc.go b/gregorian/doc.go
@@ -3,4 +3,14 @@
 // license that can be found in the LICENSE file.
 
 // Package gregorian provides utility functions for the Gregorian calendar calculations.
+// The Gregorian calendar was officially introduced in October 1582 so, strictly speaking,
+// it only applies after that date. Some countries did not switch to the Gregorian calendar
+// for many years after (such as Great Britain in 1782).
+//
+// Extending the Gregorian calendar backwards to dates preceding its official introduction
+// produces a proleptic calendar that should be used with some caution for historic dates
+// because it can lead to confusion.
+//
+// See https://en.wikipedia.org/wiki/Gregorian_calendar
+// https://en.wikipedia.org/wiki/Proleptic_Gregorian_calendar
 package gregorian