Algorithm for converting the Gregorian calendar and the lunar calendar in VB. NET

'The following is a calendar algorithm about VB.

'Date data definition method:

'The first 12 bytes represent 1-12 months for a large month or a small month, 1 for a large month for 30 days, and 0 for a small month for 29 days;

'1st digit indicates a leap month. The value 1 indicates 30 days for a large month, and the value 0 indicates 29 days for a small month;

'1970 is the month of A leap month. If it is not the month of A leap month, it is given A month. The values of 10, 11, and 12 are represented by A, B, and C, respectively, in hexadecimal notation;

'The last four digits are the Lunar New Year of the current year. January 1 The date of the Gregorian calendar. For example, the date 0131 represents January 31 .

Function GetChgDate (ByVal vDate As String, ByVal ChgType As conversion method) As String

Dim vvdate () As String = Split (vDate ,"-")

If vvdate (0)> 2011 Or vvdate (0) <1900 Then

Throw New NotSupportedException ("This function only provides calendar conversion from January 1, 1900 to January 1, 2011! ")

End If

Dim AddMonth, AddDay, AddYear, getDay, I As Integer

Dim RunYue As Boolean

Dim conDate As DateTime

Dim daList (2011) As String

DaList (1900) = "010010110110180131"

DaList (1901) = "010010101110000219"

DaList (1902) = "101001010111000208"

DaList (1903) = "010100100110150129"

DaList (1904) = "110100100110000216"

DaList (1905) = "110110010101000204"

DaList (1906) = "011010101010140125"

DaList (1907) = "010101101010000213"

DaList (1908) = "100110101101000202"

DaList (1909) = "010010101110120122"

DaList (1910) = "010010101110000210"

DaList (1911) = "101001001101160130"

DaList (1912) = "101001001101000218"

DaList (1913) = "110100100101000206"

DaList (1914) = "110101010100150126"

DaList (1915) = "101101010101000214"

DaList (1916) = "010101101010000204"

DaList (1917) = "100101101101020123"

DaList (1918) = "100101011011000211"

DaList (1919) = "010010011011170201"

DaList (1920) = "010010011011000220"

DaList (1921) = "101001001011000208"

DaList (1922) = "101100100101150128"

DaList (1923) = "011010100101000216"

DaList (1924) = "011011010100000205"

DaList (1925) = "101011011010140124"

DaList (1926) = "001010110110000213"

DaList (1927) = "100101010111000202"

DaList (1928) = "010010010111120123"

DaList (1929) = "010010010111000210"

DaList (1930) = "011001001011060130"

DaList (1931) = "110101001010000217"

DaList (1932) = "111010100101000206"

DaList (1933) = "011011010100150126"

DaList (1934) = "010110101101000214"

DaList (1935) = "001010110110000204"

DaList (1936) = "100100110111030124"

DaList (1937) = "100100101110000211"

DaList (1938) = "110010010110170131"

DaList (1939) = "110010010101000219"

DaList (1940) = "110101001010000208"

DaList (1941) = "110110100101060127"

DaList (1942) = "101101010101000215"

DaList (1943) = "010101101010000205"

DaList (1944) = "101010101101140125"

DaList (1945) = "001001011101000213"

DaList (1946) = "100100101101000202"

DaList (1947) = "110010010101120122"

DaList (1948) = "101010010101000210"

DaList (1949) = "101101001010170129"

DaList (1950) = "011011001010000217"

DaList (1951) = "101101010101000206"

DaList (1952) = "010101011010150127"

DaList (1953) = "010011011010000214"

DaList (1954) = "101001011011000203"

DaList (1955) = "010100101011130124"

DaList (1956) = "010100101011000212"

DaList (1957) = "101010010101080131"

DaList (1958) = "111010010101000218"

DaList (1959) = "011010101010000208"

DaList (1960) = "101011010101060128"

DaList (1961) = "101010110101000215"

DaList (1962) = "010010110110000205"

DaList (1963) = "101001010111040125"

DaList (1964) = "101001010111000213"

DaList (1965) = "010100100110000202"

DaList (1966) = "111010010011030121"

DaList (1967) = "110110010101000209"

DaList (1968) = "010110101010170130"

DaList (1969) = "010101101010000217"

DaList (1970) = "100101101101000206"

DaList (1971) = "010010101110150127"

DaList (1972) = "010010101101000215"

DaList (1973) = "101001001101000203"

DaList (1974) = "110100100110140123"

DaList (1975) = "110100100101000211"

DaList (1976) = "110101010010180131"

DaList (1977) = "101101010100000218"

DaList (1978) = "101101101010000207"

DaList (1979) = "100101101101060128"

DaList (1980) = "100101011011000216"

DaList (1981) = "010010011011000205"

DaList (1982) = "101001001011140125"

DaList (1983) = "101001001011000213"

DaList (1984) = "1011001001011A0202"

DaList (1985) = "011010100101000220"

DaList (1986) = "011011010100000209"

DaList (1987) = "101011011010060129"

DaList (1988) = "101010110110000217"

DaList (1989) = "100100110111000206"

DaList (1990) = "010010010111150127"

DaList (1991) = "010010010111000215"

DaList (1992) = "011001001011000204"

Dalist (1993) = "011010100101030123"

Dalist (1994) = "111010100101000210"

Dalist (1995) = "011010110010180131"

Dalist (1996) = "010110101100000219"

Dalist (1997) = "101010110110000207"

Dalist (1998) = "100100110110150128"

Dalist (1999) = "100100101110000216"

Dalist (2000) = "110010010110000205"

Dalist (2001) = "110101001010140124"

Dalist (2002) = "110101001010000212"

Dalist (2003) = "110110100101000201"

Dalist (2004) = "010110101010120122"

Dalist (2005) = "010101101010000209"

Dalist (2006) = "101010101101170129"

Dalist (2007) = "001001011101000218"

Dalist (2008) = "100100101101000207"

Dalist (2009) = "110010010101150126"

Dalist (2010) = "101010010101000214"

DaList (2011) = "101101001010000214"

AddYear = vvdate (0)

If ChgType = Conversion method.

AddMonth = Val (Mid (daList (AddYear), 15, 2 ))

AddDay = Val (Mid (daList (AddYear), 17, 2 ))

ConDate = DateSerial (AddYear, AddMonth, AddDay)

AddDay = vvdate (2)

For I = 1 To vvdate (1)-1

AddDay = AddDay + 29 + Val (Mid (daList (vvdate (0), I, 1 ))

Next I

Return DateAdd (DateInterval. Day, AddDay-1, conDate)

Else

CHUSHIHUA:

AddMonth = Val (Mid (daList (AddYear), 15, 2 ))

AddDay = Val (Mid (daList (AddYear), 17, 2 ))

ConDate = DateSerial (AddYear, AddMonth, AddDay)

Dim vtDate As DateTime

Try

VtDate = CType (vDate, DateTime)

Catch ex As Exception

Throw New NotSupportedException ("Date input error! ")

End Try

GetDay = DateDiff (DateInterval. Day, conDate, vtDate)

If getDay <0 Then AddYear = AddYear-1: GoTo CHUSHIHUA

AddDay = 1

AddMonth = 1

For I = 1 To getDay

AddDay = AddDay + 1

If AddDay = 30 + Mid (daList (AddYear), AddMonth, 1) Or (RunYue And AddDay = 30 + Mid (daList (AddYear), 13, 1) Then

If RunYue = False And AddMonth = Val ("& H" & Mid (daList (AddYear), 14, 1) Then

RunYue = True

Else

RunYue = False

AddMonth = AddMonth + 1

End If

AddDay = 1

End If

Next

Return AddYear & "-" & AddMonth & "-" & AddDay

End If

End Function

Enum Conversion Method

Lunar calendar to Gregorian calendar = 1

Gregorian to Lunar Calendar = 0

End Enum