根据待分摊费用总额、费用起止日期、待分摊归属季度，计算该季度应分摊费用。

调用《Excel·VBA自定义函数计算每月费用标准》计算每月费用标准，再调用《Excel·VBA自定义函数计算日期期间费用》计算该季度应分摊费用

注意：因保留2位小数，经monthcost、datecost计算后，分摊费用的合计数与原待分摊费用存在一定差额

Function costshare(cost1 As Double, startdate1 As Date, enddate1 As Date, quarter1 As Integer) As Double
    '函数定义costshare(待分摊费用，费用开始日期，费用结束日期，季度数)，计算该季度应分摊的费用
    '季度数：取值范围 [1,++] ，计数从开始日期当年的1季度起，即 1 为开始日期当年1季度，表示1季度应分摊费用，以此类推
    
    Dim cost As Double, startdate As Date, enddate As Date, quarter As Integer
    Dim month_cost As Double, date_quarter1 As Date, date_quarter2 As Date
    cost = cost1
    startdate = startdate1
    enddate = enddate1
    quarter = quarter1
    '以上为定义参数变量和赋值，否则无法调用其他模块定义的函数
    
    month_cost = monthcost.monthcost(cost, startdate, enddate)   '计算每月标准费用，调用其他模块的函数，句点法
    date_quarter1 = DateSerial(Year(startdate), quarter * 3 - 2, 1)   '待分摊季度初的日期
    date_quarter2 = DateSerial(Year(startdate), quarter * 3 + 1, 0)   '待分摊季度末的日期
    
    If DateDiff("d", enddate, date_quarter1) > 0 Or DateDiff("d", date_quarter2, startdate) > 0 Then
        '起止日期与待输出季度初末日期没有交集
        costshare = 0
    ElseIf DateDiff("d", date_quarter1, startdate) >= 0 And DateDiff("d", enddate, date_quarter2) >= 0 Then
        '起止日期都在待输出季度初末日期内
        costshare = cost
    ElseIf DateDiff("d", date_quarter1, startdate) >= 0 And DateDiff("d", date_quarter2, enddate) >= 0 Then
        '待输出季度仅季末日期在起止日期内
        costshare = datecost.datecost(startdate, date_quarter2, month_cost)
    ElseIf DateDiff("d", startdate, date_quarter1) >= 0 And DateDiff("d", date_quarter2, enddate) >= 0 Then
        '待输出季度初末都在起止日期内
        costshare = month_cost * 3
    ElseIf DateDiff("d", startdate, date_quarter1) >= 0 And DateDiff("d", enddate, date_quarter2) >= 0 Then
        '待输出季度仅季初在起止日期内
        costshare = datecost.datecost(date_quarter1, enddate, month_cost)
    End If
    
End Function

Sub costshare帮助信息()
    '运行一次后该帮助信息生效
    
    Dim 函数名称 As String        '函数名称
    Dim 函数描述 As String        '函数描述
    Dim 参数个数(4) As String     '函数参数描述 数组 个数
    
    函数名称 = "costshare"
    函数描述 = "根据待分摊费用总额、费用起止日期、待分摊归属季度，计算该季度应分摊费用"
    参数个数(0) = "参数1：待分摊费用，数字格式"
    参数个数(1) = "参数2：费用开始日期，日期格式"
    参数个数(2) = "参数3：费用结束日期，日期格式"
    参数个数(3) = "参数4：待分摊归属季度，自开始日期当年度1季度开始计数，数字格式"
    
    Call Application.MacroOptions(macro:=函数名称, Description:=函数描述, ArgumentDescriptions:=参数个数)
    
End Sub