Как получить секунды с эпохи (01.01.1970) в VBA?

Вот решение: http://vbcity.com/forums/t/5084.aspx

Function UnixTime() As Variant
    'The first parameter determines how the 
    ' difference will be measured in i.e. "S" for seconds
    UnixTime = DateDiff("S", "1/1/1970", Now())
End Function

Этот должен работать быстрее, чем решение DateDiff:

Private Function Long2Date(lngDate As Long) As Date
    Long2Date = lngDate / 86400# + #1/1/1970#
End Function

Private Function Date2Long(dtmDate As Date) As Long
    Date2Long = (dtmDate - #1/1/1970#) * 86400
End Function