Quarterly helper functions

c-sharp.cs

private System.DateTime GetLastDayOfMonth(int intMonth, int intYear)
{
	//todo: move to utility class
	return DateAndTime.DateSerial(intYear, intMonth + 1, 0);
}

// Quarterly helper functions:

public static int GetQuarter(DateTime originalDate)
{
	return ((originalDate.Month - 1) / 3) + 1;
}

public static DateTime AddQuarters(DateTime originalDate, int quarters)
{
	return originalDate.AddMonths(quarters * 3);
}

public static DateTime GetFirstDayOfQuarter(DateTime originalDate)
{
	return AddQuarters(new DateTime(originalDate.Year, 1, 1), GetQuarter(originalDate) - 1);
}

public static DateTime GetLastDayOfQuarter(DateTime originalDate)
{
	return AddQuarters(new DateTime(originalDate.Year, 1, 1), GetQuarter(originalDate)).AddDays(-1);
}

javascript.js

// quarterly date helpers
var getQuarter = function (originalDate) {
        var newDate = new Date(originalDate.getTime());
        var quarter = Math.floor(((newDate.getMonth()) / 3) + 1);
        return quarter;
    },
    addQuarters = function (originalDate, quarters) {
        var newDate = new Date(originalDate.getTime());
        newDate.setMonth(newDate.getMonth() + (quarters * 3));
        return newDate;
    },
    getFirstDayOfQuarter = function (originalDate) {
        var newDate = new Date(originalDate.getTime());
        var firstDay = addQuarters(new Date(newDate.getFullYear(), 0, 1), getQuarter(newDate) - 1);
        return firstDay;
    },
    getLastDayOfQuarter = function (originalDate) {
        var newDate = new Date(originalDate.getTime());
        var lastDay = addQuarters(getFirstDayOfQuarter(newDate), 1);
        lastDay.setDate(lastDay.getDate() - 1);
        return lastDay;
    };

vb.vb

Private Function GetLastDayOfMonth(ByVal intMonth As Integer, ByVal intYear As Integer) As Date
    'todo: move to utility class
    GetLastDayOfMonth = DateSerial(intYear, intMonth + 1, 0)
End Function

' Quarterly helper functions:

Public Shared Function GetQuarter(ByVal originalDate As DateTime) As Integer
    Return ((originalDate.Month - 1) \ 3) + 1
End Function

Public Shared Function AddQuarters(ByVal originalDate As DateTime, ByVal quarters As Integer) As DateTime
    Return originalDate.AddMonths(quarters * 3)
End Function

Public Shared Function GetFirstDayOfQuarter(ByVal originalDate As DateTime) As DateTime
    Return AddQuarters(New DateTime(originalDate.Year, 1, 1), GetQuarter(originalDate) - 1)
End Function

Public Shared Function GetLastDayOfQuarter(ByVal originalDate As DateTime) As DateTime
    Return AddQuarters(New DateTime(originalDate.Year, 1, 1), GetQuarter(originalDate)).AddDays(-1)
End Function