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

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 4

        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 5

I think this solution would work pretty well. It takes up more lines, but 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 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);

Answer 7

A simpler two liner with live demo here + press F8 to run .

var date = DateTime.Now; //Give you own DateTime
int offset = 2, monthsInQtr = 3;

var quarter = (date.Month + offset) / monthsInQtr; //To find which quarter 
var totalMonths = quarter * monthsInQtr;

var startDateInQtr = new DateTime(date.Year, totalMonths - offset, 1); //start date in quarter 

If you are looking at last day of the quarter use DateTime.DaysInMonth

var endDateInQtr = new DateTime(date.Year, totalMonths, DateTime.DaysInMonth(date.Year, totalMonths));

Answer 8

    public static class DateTimeExtensions
{
    public static DateTime StartOfQuarter(this DateTime _date)
    {
        var quarter = decimal.ToInt16(Math.Ceiling(_date.Month / 3.0m));
        return new DateTime(_date.Year, quarter, 1);
    }
}

use

var quarterStart = DateTime.Today.StartOfQuarter();

Answer 9

Let's begin with the start date of the quarter. I consider this one more useful, and harder to find a neat implementation for.

• Year: The input year.
• Month: The input month, minus its "overshoot" over the quarter's first month (e.g. February overshoots the quarter's starting month (January) by 1).
• Day: 1

public static DateOnly GetFirstDayOfCurrentQuarter(DateTime dateTime)
{
    var month = dateTime.Month - (dateTime.Month - 1) % 3;
    var result = new DateOnly(dateTime.Year, month, 1);

    return result;
}

By making the current month 0-based (dateTime.Month - 1), we can easily see by how much it overshoots the start of its quarter (% 3). We subtract the overshoot from the current month to get the quarter's starting month.

The quarter number (1-4) is even simpler:

var quarterNumber = (dateTime.Month - 1) / 3 + 1;

By making the current month 0-based (dateTime.Month - 1), we can easily obtain the 0-based quarter index (/ 3). We convert that to the quarter number (+ 1).

Answer 10

Here i have 3 methods. A get the current quarter number, get the start date and end date.

static (DateTime startDate, DateTime endDate) GetCurrentQuarter(DateTime date)
{
    var year = date.Year;
    var quarter = (int)Math.Ceiling(date.Month / 3d);
    var start = GetStartDateOfQuarter(year, quarter);
    var end = GetEndDateOfQuarter(year, quarter);
    return (start, end);
}

static DateTime GetStartDateOfQuarter(int year, int quarter)
{
    var month = quarter * 3 - 2;
    return new DateTime(year, month, 1);
}

static DateTime GetEndDateOfQuarter(int year, int quarter)
{
    var month = quarter * 3;
    var daysInMonth = DateTime.DaysInMonth(year, month);
    return new DateTime(year, month, daysInMonth);
}

And then for testing purposes:

var date = new DateTime(2023, 1, 1); // 2023-01-01

var (start, end) = GetCurrentQuarter(date);

Console.WriteLine("Start date of Current Quarter: {0}", start);
Console.WriteLine("End date of Current Quarter: {0}", end);