How to get the date of the next Sunday? [duplicate]
Possible Duplicate:
ASP.net get the next tuesday
Given a day of the month, how can I get the next sunday from that day?
So if I pass in Tuesday September 13th 2011, i开发者_如何学编程t will return Sept. 18th.
I use this extension method:
public static DateTime Next(this DateTime from, DayOfWeek dayOfWeek)
{
int start = (int)from.DayOfWeek;
int target = (int)dayOfWeek;
if (target <= start)
target += 7;
return from.AddDays(target - start);
}
date.AddDays(7 - (int)date.DayOfWeek)
should do it I think.
date.DayOfWeek
will return an enum value that represents the day (where 0 is Sunday).
var date = DateTime.Now;
var nextSunday = date.AddDays(7 - (int) date.DayOfWeek);
If you need nearest sunday, code little bit different (as if you're on sunday, nearest sunday is today):
var nearestSunday = date.AddDays(7 - date.DayOfWeek == DayOfWeek.Sunday ? 7 : date.DayOfWeek);
/// <summary>
/// Finds the next date whose day of the week equals the specified day of the week.
/// </summary>
/// <param name="startDate">
/// The date to begin the search.
/// </param>
/// <param name="desiredDay">
/// The desired day of the week whose date will be returneed.
/// </param>
/// <returns>
/// The returned date is on the given day of this week.
/// If the given day is before given date, the date for the
/// following week's desired day is returned.
/// </returns>
public static DateTime GetNextDateForDay( DateTime startDate, DayOfWeek desiredDay )
{
// (There has to be a better way to do this, perhaps mathematically.)
// Traverse this week
DateTime nextDate = startDate;
while( nextDate.DayOfWeek != desiredDay )
nextDate = nextDate.AddDays( 1D );
return nextDate;
}
Source:
http://angstrey.com/index.php/2009/04/25/finding-the-next-date-for-day-of-week/
Here's the code:
int dayOfWeek = (int) DateTime.Now.DayOfWeek;
DateTime nextSunday = DateTime.Now.AddDays(7 - dayOfWeek).Date;
Get first the numerical value of the day of the week, in your example: Tuesday = 2
Then subtract it from Sunday, 7 -2 = 5 days to be added to get the next Sunday date. :)
DateTime dt=dateTime;
do {
dt=dt.AddDays(1);
} while(dt.DayOfWeek!= DayOfWeek.Sunday);
// 'dt' is now the next Sunday
Your question isn't clear whether the same date is returned if the date is already a Sunday; I assume no, but change the above to a while loop if I'm wrong.
Example using recursion
private static DateTime GetNextSunday(DateTime dt)
{
var tomorrow = dt.AddDays(1);
if (tomorrow.DayOfWeek != DayOfWeek.Sunday)
{
GetNextSunday(tomorrow);
}
return tomorrow;
}
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