wmf2014版主：系统日期修改到5月28日就提示下标越界！

犯低级错误了，把pb函数里  j = Int(Abs(DateDiff("d", d, sdate)) / 7)改成  j = (Int(Abs(DateDiff("d", d, sdate)) / 7)) mod 3就可以了，下一句k=j mod 3可不要。

wmf2014版主：以下代码在测试过程中，发现用Date获取系统时间的时候会出错，比日在2018-5-7起始的时候正常显示，把系统时间修改到2018-5-8软件开始自动倒一次班，然后就在2018-5-15以及2018-5-22等有规律的在每周2开始倒班。

Function pb(sdata As String, sdate As Date) As String
   '本函数按照要求输出指定日期排班结果
  'sdata为起始排班数据，格式是“起始日期,早班,中班,晚班"，如"2017-5-3,张某,李某,王某"
  'sdate为你指定的任何日期，返回结果为指定日期排班结果，早中晚班用逗号隔开，如"早班：王某,中班：李某,晚班：张某"
  Dim i As Integer, j As Integer, k As Integer, d As String, b() As String, c() As String
   b = Split(sdata, ",")
   c = Split("早班,中班,夜班", ",")
   d = b(0)
   i = Weekday(d)
   While i <> 3
     d = DateAdd("d", -1, d)
     i = Weekday(d)
   Wend
   j = (Int(Abs(DateDiff("d", d, sdate)) / 7)) Mod 3
   i = 0
   b(0) = ""
   While i < 3
     b(0) = b(0) & c(i) & "：" & b(j + 1) & ","
     j = j + 1
     If j > 2 Then j = 0
     i = i + 1
   Wend
   pb = b(0)
End Function

Private Sub Command1_Click()
   Dim a As String, b() As String
   a = "2018-5-7,张某,李某,王某"
   b = Split(pb(a, Date), ",")
   Label1.Caption = Date & "日" & b(0)
   Label2.Caption = Date & "日" & b(1)
   Label3.Caption = Date & "日" & b(2)
End Sub

Private Sub Timer1_Timer() '修改系统日期的时候，方便自动测试！
Command1_Click
End Sub

如果用你第一次发的程序，人工修改日期，那就相当准确

Function pb(sdata As String, sdate As Date) As String
   '本函数按照要求输出指定日期排班结果
  'sdata为起始排班数据，格式是“起始日期,早班,中班,晚班"，如"2017-5-3,张某,李某,王某"
  'sdate为你指定的任何日期，返回结果为指定日期排班结果，早中晚班用逗号隔开，如"早班：王某,中班：李某,晚班：张某"
  Dim i As Integer, j As Integer, k As Integer, d As String, b() As String, c() As String
   b = Split(sdata, ",")
   c = Split("早班,中班,晚班", ",")
   d = b(0)
   i = Weekday(d)
   While i <> 2
     d = DateAdd("d", -1, d)
     i = Weekday(d)
   Wend
   j = (Int(Abs(DateDiff("d", d, sdate)) / 7)) Mod 3
   i = 0
   b(0) = ""
   While i < 3
     b(0) = b(0) & c(i) & "：" & b(j + 1) & ","
     j = j + 1
     If j > 2 Then j = 0
     i = i + 1
   Wend
   pb = b(0)
End Function

Private Sub Command1_Click()
   Dim a As String
   a = "2018-5-21,【张某】,【李某】,【王某】"
   Label1.Caption = pb(a, "2018-5-7") '只要起始数据定了，2018-5-7这个日期可以随便换，都能正确返回该日期所在周的排班结果
End Sub

我怎么觉得你在第一段代码里就是要星期二倒班呢？5月7号是星期一，那天排的班不应该8号倒班的，“While i <> 3”这句你修改了，原代码是“While i <>2”。