Calculate the start-date and name of a quarter from a given date

Question

How can I find the start-date and name (1, 2, 3, etc.) of a quarter from a given date?

Answer 1

Something like (untested):

DateTime date;
int quarterNumber = (date.Month-1)/3+1;
DateTime firstDayOfQuarter = new DateTime(date.Year, (quarterNumber-1)*3+1,1);
DateTime lastDayOfQuarter = firstDayOfQuarter.AddMonths(3).AddDays(-1);

Answer 2

int GetQuarterName(DateTime myDate)
{
    return (int)Math.Ceiling(myDate.Month / 3.0);
}

DateTime GetQuarterStartingDate(DateTime myDate)
{
    return new DateTime(myDate.Year,(3*GetQuarterName(myDate))-2,1);
}

GetQuarterName gets the "next" integer value of the current month number / 3.

GetQuarterStartingDate uses the output from GetQuarterName to work out the month value, the year part of the original date, and 1 to represent the first day of the month to return.

(Apologies for making no sense, I have flu. :( )

Answer 3

        var date = new DateTime(2015, 3, 15);

        var quarter = (date.Month + 2) / 3;

        var quarterStartMonth = 3 * quarter - 2;

        var quarterStartDate = new DateTime(date.Year, quarterStartMonth, 1);

Answer 4

I think this solution would work pretty well. It takes up more line, bus is very verbose! `

private DateTime GetFirstDayOfYearlyQuarter(DateTime value)
{
    switch (value.Month)
    {
        case 1:
        case 2:
        case 3:
            return new DateTime(value.Year, 1, 1);
        case 4:
        case 5:
        case 6:
            return new DateTime(value.Year, 4, 1);
        case 7:
        case 8:
        case 9:
            return new DateTime(value.Year, 7, 1);
        case 10:
        case 11:
        case 12:
            return new DateTime(value.Year, 10, 1);
        default:
            throw new Exception(@"¯\_(ツ)_/¯");
    }
}

`

P.S. This only finds first day of quarter, but you can easily extend this to find number of quarter, etc.

Answer 5

https://msdn.microsoft.com/en-us/library/ms127415(v=vs.110).aspx

using Microsoft.VisualBasic;
var quarter = DateAndTime.DatePart(DateInterval.Quarter, (DateTime)dateTimePickerDateTime.Value);

Answer 6

DateTime date;
int quarterNumber = (date.Month-1)/3+1;
DateTime firstDayOfQuarter = new DateTime(date.Year, (quarterNumber-1)*3+1,1);
DateTime lastDayOfQuarter = firstDayOfQuarter.AddMonths(3).AddDays(-1);