Dim oldDate As Date
Dim oldWeekDay As Integer
Dim Den As String
Dim Mesyac As Integer
Dim God As Integer
Den = Text1.Text
Mesyac = Label4.Caption
God = Text3.Text

oldDate = # 6 / 19 / 2011 #
oldWeekDay = Weekday(oldDate)
Print oldDate
If oldWeekDay = "2" Then Label5.Caption = "Понедельник"
If oldWeekDay = "3" Then Label5.Caption = "Вторник"
If oldWeekDay = "4" Then Label5.Caption = "Среда"
If oldWeekDay = "5" Then Label5.Caption = "Четверг"
If oldWeekDay = "6" Then Label5.Caption = "Пятница"
If oldWeekDay = "7" Then Label5.Caption = "Суббота"
If oldWeekDay = "1" Then Label5.Caption = "Воскресенье"

[src vba]?WeekdayName( 5 )
пятница

Label4.Caption = Day(Date) + " " + Month(Date)

Label4.Caption = "Сейчас:   " & Day(Date) & " Число"

Dim Razica As Integer
Raznica = Year(Date) - God
Print Raznica

Dim Razica As Integer
Raznica = Year(Date) - God
Print Raznica

If Len(text20.text) <  2  Then text20.text = "0" & text20.text

& text20.text

Dim Den As Integer
Dim Mesyac As Integer
Dim God As Integer
Den = Text1.Text
Mesyac = Mes
God = Text3.Text
Dim Dennow As Integer
Dim Mesyacnow As Integer
Dim Godnow As Integer
Dennow = Day(Date)
Mesyacnow = Month(Date)
Godnow = Year(Date)

If Len(Den) <  2  Then Den = "0" & Den
If Len(Mesyac) <  2  Then Mesyac = "0" & Mesyac
If Len(God) <  2  Then God = "0" & God
If Len(Dennow) <  2  Then Dennow = "0" & Dennow
If Len(Mesyacnow) <  2  Then Mesyacnow = "0" & Mesyacnow
If Len(Godnow) <  2  Then Godnow = "0" & Godnow
Label8.Caption = Val(Godnow & Mesyacnow & Dennow) - Val(God & Mesyac & Den)

Потому что в поле Text2.txt могут вписать такие значения
например:
Dim Mes As String
Mes = ""
If Text2.Text = "1" Or Text2.Text = "01" Or Text2.Text = "Январь" Or Text2.Text = "Января" Then Mes = "01"
If Mes = "01" Then Text2.Text = "Январь"
Dim Mesyac As Byte
Mesyac = Mes

Dim Mes As String
Mes = ""
If Text2.Text = "1" Or Text2.Text = "01" Or Text2.Text = "Январь" Or Text2.Text = "Января" Then Mes = "01"
If Mes = "01" Then Text2.Text = "Январь"

'остальные расписывать не буду и так понятно что по анологии

Dim Den As Byte
Dim Mesyac As Byte
Dim God As Integer
Den = Text1.Text
Mesyac = Mes
God = Text3.Text

Dim Dennow As Byte
Dim Mesyacnow As Byte
Dim Godnow As Integer
Dennow = Day(Date)
Mesyacnow = Month(Date)
Godnow = Year(Date)

If Len(Den) <  2  Then Den =  0  & Den
If Len(Mesyac) <  2  Then Mesyac =  0  & Mesyac
If Len(God) <  2  Then God =  0  & God
If Len(Dennow) <  2  Then Dennow =  0  & Dennow
If Len(Mesyacnow) <  2  Then Mesyacnow =  0  & Mesyacnow
If Len(Godnow) <  2  Then Godnow =  0  & Godnow
Label8.Caption = Val(Godnow & Mesyacnow & Dennow) - Val(God & Mesyac & Den)

Dim A, retval
A = (Mesyac Den,God)
Print A
retval = CDate(A)
Print retval

A = (Mesyac Den,God)

Dim Dennow As Byte
Dim Mesyacnow As Byte
Dim Godnow As Integer
Dennow = Day(Date)
Mesyacnow = Month(Date)
Godnow = Year(Date)
Dim A, retval, Anow, retvalnow, Razn
A = (Mesyac & " " & Den & " " & God)
Anow = (Mesyacnow & " " & Dennow & " " & Godnow)
retval = CDate(A)
retvalnow = CDate(Anow)
Label8.Caption = retvalnow - retval

Dim A, retval, Anow, retvalnow
A = (Mesyac & " " & Den & " " & God)
Anow = (Mesyacnow & " " & Dennow & " " & Godnow)
retval = CDate(A)
retvalnow = CDate(Anow)
Label8.Caption = DateDiff(Interval,retvalnow,retval,[FirstDayOfWeek],[FirstWeekOfYear]) 

Пример 
' Вычисляем сколько дней осталось до 21 века
Dim Today as Date' сегодняшний день
Dim Millenium As Date' 1 день 21 века
Dim retval' возвращаемое значение
Today=Date ' узнаем текущую системную дату
Millenium="01.01.01"
retval=DateDiff("d",Today,Millenium)
Form1.Caption = CStr(retval)  ' выводим в заголовке формы

Dim Dennow As Byte
Dim Mesyacnow As Byte
Dim Godnow As Integer
Dennow = Day(Date)
Mesyacnow = Month(Date)
Godnow = Year(Date)
Dim A As String 'Вот тут не знаю вроде String должен быть?
Dim Anow As String 'Вот тут не знаю вроде String должен быть?
Dim retvalnow As Date
Dim retval As Date
Dim Razn

A = (Mesyac & " " & Den & " " & God)
Anow = (Mesyacnow & " " & Dennow & " " & Godnow)
retval = CDate(A)
retvalnow = CDate(Anow)
Razn = DateDiff("y", retval, retvalnow)
Label8.Caption = Razn

RaznGod = Razn / "365,24219"
Label8.Caption = RaznGod

Dim Dennow As Byte
Dim Mesyacnow As Byte
Dim Godnow As Integer
Dennow = Day(Date)
Mesyacnow = Month(Date)
Godnow = Year(Date)

A = (God & " " & Mesyac & " " & Den)
Anow = (Godnow & " " & Mesyacnow & " " & Dennow)
retval = CDate(A)
retvalnow = CDate(Anow)
Razn = DateDiff("yyyy", retval, retvalnow)
Label8.Caption = "Число целых лет: " & Razn