I'm having strange behavior of DateTime in c#.
I'm trying to initialize a datepicker in January. So I make a new date:
DateTime MyDate = new DateTime(2017, 0, 15);
But I get this exception:
System.ArgumentOutOfRangeException: Year, Month, and Day parameters describe an un-representable DateTime.
If I use (2017, 1, 15) it works but the time dialog, initialized with:
DatePickerDialog dialog = new DatePickerDialog(
Activity,
this,
MyDate.Year,
MyDate.Month,
MyDate.Day);
Goes on February.
Well I tried to "cheat" and did:
DateTime MyDate = new DateTime(2017, 1, 15);
DateTime = DateTime.AddMonths(-1);
No error, but the date picker goes on February.
The only way to have January is:
DateTime MyDate = new DateTime(2017, 12, 15);
What am I doing wrong?
DateTime.Month is a value between 1 and 12, which aligns with what most people think a month 'number' is.
Per the android docs, theDatePickerDialog constructor you are calling accepts a zero-based month. It accepts values in the range 0-11, so you need to subtract one from the DateTime.Month.
DatePickerDialog dialog = new DatePickerDialog(Activity,
this, MyDate.Year, MyDate.Month - 1, MyDate.Day);
The issue is how the DateTime object treats month values (1-12) and how the DatePickerDialog treats month values (0-11).
DateTime constructor:
strange behavior of DateTime
DateTime MyDate = new DateTime(2017, 0, 15);
If we take a look at the DateTime constructor, it is clearly stated that the month value should be 1 through 12, which is not valid in your case and hence the exception. We can correct it as below:
DateTime MyDate = new DateTime(2017, 1, 15);
DatePickerDialog constructor:
Exception (or strange behavior) will arise when we try - new DatePickerDialog in combination with the month value of DateTime as the constructor of DatePickerDialog is expecting the month values from 0-11.
It is stated that int: the initially selected month (0-11 for compatibility with MONTH)
The approach which can then be followed is to give the correct index for month to DatePickerDialog constructor as below:
DateTime MyDate = new DateTime(2017, 1, 15);
DatePickerDialog dialog = new DatePickerDialog(Activity,
this,
MyDate.Year,
MyDate.Month - 1,
MyDate.Day);
Related
When converting the current date and time, got from DateTime.Now, TimeZoneInfo.ConvertTimeToUtc(DateTime.Now) converts it correctly.
However, if a DateTime object is created, it does not convert it, it leaves it the same:
// get the local time as dd/mm/yyyy hh:mm:ss tt
DateTime dateTime = new DateTime(2020, 2, 5, 11, 59, 53, 0, DateTimeKind.Local); // tried with and without DateTimeKind specified
Console.WriteLine(dateTime.ToString());
// convert it to UTC
DateTime UTCdateTime = TimeZoneInfo.ConvertTimeToUtc(dateTime);
Console.WriteLine(UTCdateTime.ToString());
This prints:
2/5/2020 11:59:53 AM
2/5/2020 11:59:53 AM
The second timestamp should be UTC.
Why is this?
Note: the values plugged in above I was using to test. I need to get them from dateTimePicker controls.
I have to calculate the date or create a date which is 10 days into next month. I have with me month and year. If the month is April and year is 2019 I need a date which is 10th of may 2019.
You can simply use the methods available in the DateTime structure to do math with dates
// As example, replaces it with whatever date you have
DateTime current = new DateTime(2019,4,5);
DateTime next = new DateTime(current.Year, current.Month, 1).AddMonths(1).AddDays(9);
You can use AddMonths() and AddDays() extension method of DateTime.
From MSDN :
AddMonths() : Returns a new DateTime that adds the specified number of
months to the value of this instance.
AddDays() : Returns a new DateTime that adds the specified number of
days to the value of this instance.
//Considered this is your Current date
DateTime existingDate = new DateTime(2019, 4, 1);
//Below code will add +1 month to current month and +9 days to current date.
var result = existingDate.AddMonths(1).AddDays(9);
Output :
CurrentDate : 4/1/2019 12:00:00 AM
Next Date (+1 month and +9 days) :5/10/2019 12:00:00 AM
POC : .net Fiddle
var dateNow = DateTime.Now.AddMonths(1);
var date = new DateTime(dateNow.Year, dateNow.Month, 10);
Try this:
DateTime dt = new DateTime(2019, 04, 01);
DateTime newDT = dt.AddMonths(1).AddDays(9);
How can I set certain DateTime value to tomorrow 9:00 AM
For example:
DateTime startTime = new DateTime.Now.AddDays(1).//setTime to 9:00 AM
Is there some SetDateTime value functionality that I don't know?
You can use two methods
DateTime.Today.AddDays(1).AddHours(9)
You can use this DateTime constructor like;
DateTime tomorrow = new DateTime(DateTime.Now.Year,
DateTime.Now.Month,
DateTime.Now.Day + 1,
9,
0,
0);
Console.WriteLine(tomorrow);
Output will be;
18.03.2014 09:00:00
As CompuChip mentioned, this throws exception if the current day is the last day of the month.
Better you can use DateTime.Today property with AddDays(1) and AddHours(9) because it get's to midnight of the current day. Like;
DateTime tomorrow = DateTime.Today.AddDays(1).AddHours(9);
DateTime dt=DateTime.Now;
DateTime Tomorrow = new DateTime(dt.Year,dt.Month,dt.Day+1,9,0,0);
How do I use a specific date as an input value?
var experiment1 = WorkingWithDates.GetDisplayString("London", DateTime.Today, 45.00);
Later on, I'll be convering it to a string, but I need it to be input as a DateTime.
public static string GetDisplayString(string city, DateTime date, double temp)
{
}
I'm using DateTime.Today as a placeholder, simply because it works. The thing is, I need it input as a specific day of a month of a year. (I've tried using (10, 10, 10) but it simply gives me a compiler error.
Edit.: I can't believe I did not figure out all I need to do is to add "new". Thanks folks
In (10, 10, 10) do you want the year 10?
Use the constructor that takes in a year, a month and a day. As below.
DateTime dt = new DateTime(2013, 12, 12);
then call your method
var experiment1 = WorkingWithDates.GetDisplayString("London", dt, 45.00);
PS: If you want year 10
DateTime dt = new DateTime(10, 10, 10);
will work. The year will be 0010
WorkingWithDates.GetDisplayString("London", DateTime.Today, 45.00);
you need a DateTime object to be used in place of DateTime.Today, so construct your instance using
DateTime newdate = new DateTime(2013,10,10) // year, month , day
and then
WorkingWithDates.GetDisplayString("London", newdate, 45.00);
Would appreciate it if anyone can help me figure out to substract 2 datetime fields to get the days left difference.
This is very easy to do with C#. For comparing DateTimes, we have a class called TimeSpan. The TimeSpan structure, in this case, would be defined as the difference between your two datetimes.
Let's say that your DateTimes are called start and end.
DateTime start = new DateTime(2009, 6, 14);
DateTime end = new DateTime(2009, 12, 14);
We have established our DateTimes to June 14, 2009 and December 14, 2009.
Now, let's find the difference between the two. To do this, we create a TimeSpan:
TimeSpan difference = end - start;
With this TimeSpan object, you can express the difference in times in many different ways. However, you specifically asked for the difference in days, so here's how you can get that:
Console.WriteLine("Difference in days: " + difference.Days);
Thus, the property is called TimeSpan.Days.
Final Code
//establish DateTimes
DateTime start = new DateTime(2009, 6, 14);
DateTime end = new DateTime(2009, 12, 14);
TimeSpan difference = end - start; //create TimeSpan object
Console.WriteLine("Difference in days: " + difference.Days); //Extract days, write to Console.
For more information on using the TimeSpan structure, see this MSDN documentation (especially the C# examples).
Hope I helped!
UPDATE: Some answers have suggested taking doing subtraction in one step, such as with:
int days = (dt2 - dt1).Days;
or
int numDaysDiff = Math.Abs(date2.Subtract(date1).Days);
However, they are the same thing as in my answer, only shortened. This is because the DateTime.Subtract() method and the subtraction operator of DateTimes returns a TimeSpan, from which you can then access the amount of days. I have specifically used the longer approach in my code sample so that you clearly understand what is going on between your DateTime and TimeSpan objects and how it all works. Of course, the other approaches I just mentioned are fine, too.
UPDATE #2:
A very similar question was asked before, and it can be found here. However, the main point of that question was why the code sample (which is essentially equivalent to that of all the answers) sometimes provides an answer which is a day off. I think this is also important to this question.
As the main answer to the other question suggests, you can use this code:
int days = (int)Math.Ceiling(difference.TotalDays);
This code uses Math.Ceiling, which, according to MSDN, is:
Returns the smallest integral value
that is greater than or equal to the
specified double-precision
floating-point number.
How Do You Want to Count the Days?
Thus, we now have an issue with how you want to count the days. Do you want to count part of a day (such as .5 of a day) as:
A full day - this would use Math.Ceiling to round up TimeSpan.TotalDays, so that you're counting started days.
Part of a day - you can just return the TimeSpan.TotalDays (not rounded) as a decimal (in the double datatype)
Nothing - you can ignore that part of a day and just return the TimeSpan.Days.
Here are code samples for the above:
Counting as a full day (using Math.Ceiling() to round up):
//establish DateTimes
DateTime start = new DateTime(2009, 6, 14);
DateTime end = new DateTime(2009, 12, 14);
TimeSpan difference = end - start; //create TimeSpan object
int days = (int)Math.Ceiling(difference.TotalDays); //Extract days, counting parts of a day as a full day (rounding up).
Console.WriteLine("Difference in days: " + days); //Write to Console.
Counting as part of a day (NOT using Math.Ceiling(), instead leaving in decimal form as a part of a day):
//establish DateTimes
DateTime start = new DateTime(2009, 6, 14);
DateTime end = new DateTime(2009, 12, 14);
TimeSpan difference = end - start; //create TimeSpan object
double days = difference.TotalDays; //Extract days, counting parts of a day as a part of a day (leaving in decimal form).
Console.WriteLine("Difference in days: " + days); //Write to Console.
Counting as nothing of a day (rounding down to the number of full days):
//establish DateTimes
DateTime start = new DateTime(2009, 6, 14);
DateTime end = new DateTime(2009, 12, 14);
TimeSpan difference = end - start; //create TimeSpan object
int days = difference.TotalDays; //Extract days, counting parts of a day as nothing (rounding down).
Console.WriteLine("Difference in days: " + days); //Write to Console.
Use
TimeSpan
DateTime departure = new DateTime(2010, 6, 12, 18, 32, 0);
DateTime arrival = new DateTime(2010, 6, 13, 22, 47, 0);
TimeSpan travelTime = arrival - departure;
The easiest way out is, making use of TimeSpan().
This Subtract function will return you the difference between two dates in terms of time span. Now you can fetch fields like days, months etc. To access days you can make use of
Here is the sample code;
VB.Net code;
Dim tsTimeSpan As TimeSpan
Dim ldDate1 as Date
Dim ldDate2 as Date
'Initialize date variables here
tsTimeSpan = ldDate1 .Subtract(ldDate2)
Dim NumberOfDays as integer = tsTimeSpan.days
C#.Net code;
DateTime lDate1;
DateTime lDate2;
TimeSpan tsTimeSpan ;
int NumberOfDays;
//Initialize date variables here
tsTimeSpan = ldDate1 .Subtract(ldDate2);
NumberOfDays = tsTimeSpan.days;
DateTime dt1 = new DateTime(2009,01,01,00,00,00);
DateTime dt2 = new DateTime(2009,12,31,23,59,59);
int days = (dt2 - dt1).Days;
Number of Days Difference
These answers take the number of days as an int from the System.TimeSpan structure that is the result of subtracting two System.DateTime fields...
Quick answer - gets the number of days difference.
int numDaysDiff = date2.Subtract(date1).Days;
Alternate answer - uses Math.Abs to ensure it's not a negative number, just in case the dates might be supplied in either order.
int numDaysDiff = Math.Abs( date2.Subtract(date1).Days );
Some sample data to finish it off using System namespace:
// sample data
DateTime date1 = DateTime.Now;
DateTime date2 = DateTime.Now.AddDays(10);
MSDN References (and more sample code ):
System.TimeSpan structure
System.DateTime structure
System.Math.Abs(..) method
DateTime theDate = DateTime.Today;
int datediff = theDate.Subtract(expiryDate).Negate().Days;
if expiryDate > theDate then you get Negative value: -14
expiryDate is less than theDate then you get positive value: 14
You May obviously want this in a scenario such as
Send a Notification Email 14days before expiry
Send another notification Email 14 days after expiry
You need a difference that could be negative value
You should look at TimeSpan.
To get the exact days ignoring the time section
DateTime d1 = Convert.ToDateTime(DateTime.Now.ToShortDateString());
DateTime d2 = Convert.ToDateTime(DateTime.Now.AddDays(46).ToShortDateString());
var days = Convert.ToInt32(d2.Subtract(d1).TotalDays)