计算时差超过24小时

时间:2016-10-04 14:57:38

标签: ms-access ms-access-2010

我遇到了一个问题,我试图以秒为单位计算时差,然后在报告中(访问报告)我将这些秒数相加并将其格式化为hh:nn:ss。

然而,我收集两个字段之间时间差的计算字段有时会超过24小时,从而抛出时差。

我正在使用DateDiff函数--- DateDiff(" s",[BeginningTime],[EndingTime])

当涉及超过24小时的情况时,我该怎么办?

两个字段BeginningTime和EndingTime以AM / PM格式存储。我不认为这应该是重要的。

1 个答案:

答案 0 :(得分:2)

您可以使用以下功能:

Public Function FormatHourMinute( _
  ByVal datTime As Date, _
  Optional ByVal strSeparator As String = ":") _
  As String

' Returns count of days, hours and minutes of datTime
' converted to hours and minutes as a formatted string
' with an optional choice of time separator.
'
' Example:
'   datTime: #10:03# + #20:01#
'   returns: 30:04
'
' 2005-02-05. Cactus Data ApS, CPH.

  Dim strHour       As String
  Dim strMinute     As String
  Dim strHourMinute As String

  strHour = CStr(Fix(datTime) * 24 + Hour(datTime))
  ' Add leading zero to minute count when needed.
  strMinute = Right("0" & CStr(Minute(datTime)), 2)
  strHourMinute = strHour & strSeparator & strMinute

  FormatHourMinute = strHourMinute

End Function

此表达式为文本框的 ControlSource

=FormatHourMinute([EndingTime]-[BeginningTime])

但是(见注释)这个简单的表达式仅对正数值的日期有效,这些日期是1899-12-30之后的日期。

要涵盖所有日期,您需要一个合适的方法来计算时间跨度,并且可以使用此函数完成:

' Converts a date value to a timespan value.
' Useful only for date values prior to 1899-12-30 as
' these have a negative numeric value.
'
'   2015-12-15. Gustav Brock, Cactus Data ApS, CPH.
'
Public Function DateToTimespan( _
    ByVal Value As Date) _
    As Date

    ConvDateToTimespan Value

    DateToTimespan = Value

End Function


' Converts a date value by reference to a linear timespan value.
' Example:
'
'   Date     Time  Timespan      Date
'   19000101 0000  2             2
'
'   18991231 1800  1,75          1,75
'   18991231 1200  1,5           1,5
'   18991231 0600  1,25          1,25
'   18991231 0000  1             1
'
'   18991230 1800  0,75          0,75
'   18991230 1200  0,5           0,5
'   18991230 0600  0,25          0,25
'   18991230 0000  0             0
'
'   18991229 1800 -0,25         -1,75
'   18991229 1200 -0,5          -1,5
'   18991229 0600 -0,75         -1,25
'   18991229 0000 -1            -1
'
'   18991228 1800 -1,25         -2,75
'   18991228 1200 -1,5          -2,5
'   18991228 0600 -1,75         -2,25
'   18991228 0000 -2            -2
'
'   2015-12-15. Gustav Brock, Cactus Data ApS, CPH.
'
Public Sub ConvDateToTimespan( _
    ByRef Value As Date)

    Dim DatePart    As Double
    Dim TimePart    As Double

    If Value < 0 Then
        ' Get date (integer) part of Value shifted one day
        ' if a time part is present as -Int() rounds up.
        DatePart = -Int(-Value)
        ' Retrieve and reverse time (decimal) part.
        TimePart = DatePart - Value
        ' Assemble date and time part to return a timespan value.
        Value = CDate(DatePart + TimePart)
    Else
        ' Positive date values are identical to timespan values by design.
    End If

End Sub

然后你的表情看起来像:

=FormatHourMinute(DateToTimespan([EndingTime])-DateToTimespan([BeginningTime]))

对于Gord的示例值#1899-12-28 01:00:00##1899-12-27 23:00:00#,将返回2:00。