This formula calculates the date of the First Day of Advent, however, as with any Calendrical Calculation, programmers need to be aware of certain limitations.

• These results provide the dates determined by the Catholic Church. (Nearest Sunday to 30 November)
• Non-religious determinations and many advent calendars always assign the fixed date 1 December to the start of advent
• Most applications agree that the last day of Advent will always be 24 December
• The modern (Gregorian) calendar was not used until 15 Oct 1582, and many countries retained the old (Julian) calander for centuries afterwards. The formula calculates Gregorian dates - The UK switched calendars in 1752 and the formula can only be used in the UK for dates after 1752.

Public Function AdventStart(yyyy As Integer) As Date
 Dim dat as new Date(yyyy,11,27,12,0,0,0,0)
 While dat.DayOfWeek <> DayOfWeek.Sunday
  dat = dat.AddDays(1)
 End While
 Return dat
End Function
  

 
The following feast dates can be calculated using the Easter Function.

• Feast/festival dates relate to the UK(unless otherwise stated)
• Some countries/religions will celebrate festivals on different days to the UK

'yyyy = year (as Integer)
Dim FirstSundayOfAdvent as Date = Advent(yyyy)
'First Sunday is also known as Hope Sunday<br />
Dim SecondSundayOfAdvent as Date = Advent(yyyy).AddDays(7)
'Second Sunday is also known as Peace Sunday
Dim ThirdSundayOfAdvent as Date = Advent(yyyy).AddDays(14)
'Third Sunday is also known as Joy Sunday
'Third Sunday is also known as Gaudete Sunday
Dim FourthSundayOfAdvent as Date = Advent(yyyy).AddDays(14)
'Fourth Sunday is also known as Love Sunday
  

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