Try this code in a Workspace: |aDate bDate| Transcript open. aDate := Date fromString: '02.25.2011'. Transcript cr; show: aDate; cr. bDate := aDate subtractDays: 734503. Transcript show: bDate; cr; show: 'Year zero! Which calendar does Pharo officially use?'.

From http://en.wikipedia.org/wiki/0_(year):

"Year zero" does not exist in the widely used Gregorian calendar or in its predecessor, the Julian calendar. Under those systems, the year 1 BC is followed by AD 1. However, there is a year zero in astronomical year numbering (where it coincides with the Julian year 1 BC) and in ISO 8601:2004 (where it coincides with the Gregorian year 1 BC) as well as in all Buddhist and Hindu calendars. -- View this message in context: http://forum.world.st/Which-calendar-does-Pharo-officially-use-tp3323638p332... Sent from the Pharo Smalltalk mailing list archive at Nabble.com.