>有人有按月返回"月中的一周"的函数吗?搜索的大多数函数从 1 日开始。我想按周去,即2018年3月1日将是2月的第5周。3 月的第 1 周从 3 月 4 日开始。
我该怎么做?
首先找到该月日期的前一个星期日,因为此日期可能位于上个月:
DateAdd("d", 1 - Weekday(DateOfMonth), DateOfMonth)
然后使用此泛型函数查找每月的第一个星期日:
' Calculates the date of the occurrence of Weekday in the month of DateInMonth.
'
' If Occurrence is 0 or negative, the first occurrence of Weekday in the month is assumed.
' If Occurrence is 5 or larger, the last occurrence of Weekday in the month is assumed.
'
' If Weekday is invalid or not specified, the weekday of DateInMonth is used.
'
' 2016-06-09. Gustav Brock, Cactus Data ApS, CPH.
'
Public Function DateWeekdayInMonth( _
ByVal DateInMonth As Date, _
Optional ByVal Occurrence As Integer, _
Optional ByVal Weekday As VbDayOfWeek = -1) _
As Date
Const DaysInWeek As Integer = 7
Dim Offset As Integer
Dim Month As Integer
Dim Year As Integer
Dim ResultDate As Date
' Validate Weekday.
Select Case Weekday
Case _
vbMonday, _
vbTuesday, _
vbWednesday, _
vbThursday, _
vbFriday, _
vbSaturday, _
vbSunday
Case Else
' Zero, none or invalid value for VbDayOfWeek.
Weekday = VBA.Weekday(DateInMonth)
End Select
' Validate Occurence.
If Occurrence <= 0 Then
Occurrence = 1
ElseIf Occurrence > 5 Then
Occurrence = 5
End If
' Start date.
Month = VBA.Month(DateInMonth)
Year = VBA.Year(DateInMonth)
ResultDate = DateSerial(Year, Month, 1)
' Find offset of Weekday from first day of month.
Offset = DaysInWeek * (Occurrence - 1) + (Weekday - VBA.Weekday(ResultDate) + DaysInWeek) Mod DaysInWeek
' Calculate result date.
ResultDate = DateAdd("d", Offset, ResultDate)
If Occurrence = 5 Then
' The latest occurrency of Weekday is requested.
' Check if there really is a fifth occurrence of Weekday in this month.
If VBA.Month(ResultDate) <> Month Then
' There are only four occurrencies of Weekday in this month.
' Return the fourth as the latest.
ResultDate = DateAdd("d", -DaysInWeek, ResultDate)
End If
End If
DateWeekdayInMonth = ResultDate
End Function
最后,将这些组合起来并使用 DateDiff 获取星期日的计数,并添加 1(一(以获得周数:
MonthWeekNumber = 1 + DateDiff("w", DateWeekdayInMonth(DateAdd("d", 1 - Weekday(DateOfMonth), DateOfMonth), 1, vbSunday), DateOfMonth)