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

    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();