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)
Related
How do I get the time difference between two DateTime objects using C#?
The following example demonstrates how to do this:
DateTime a = new DateTime(2010, 05, 12, 13, 15, 00);
DateTime b = new DateTime(2010, 05, 12, 13, 45, 00);
Console.WriteLine(b.Subtract(a).TotalMinutes);
When executed this prints "30" since there is a 30 minute difference between the date/times.
The result of DateTime.Subtract(DateTime x) is a TimeSpan Object which gives other useful properties.
You want the TimeSpan struct:
TimeSpan diff = dateTime1 - dateTime2;
A TimeSpan object represents a time interval (duration of time or elapsed time) that is measured as a positive or negative number of days, hours, minutes, seconds, and fractions of a second. The TimeSpan structure can also be used to represent the time of day, but only if the time is unrelated to a particular date.
There are various methods for getting the days, hours, minutes, seconds and milliseconds back from this structure.
If you are just interested in the difference then:
TimeSpan diff = (dateTime1 - dateTime2)).Duration();
will give you the positive difference between the times regardless of the order.
If you have just got the time component but the times could be split by midnight then you need to add 24 hours to the span to get the actual difference:
TimeSpan diff = dateTime1 - dateTime2;
if (diff < 0)
{
diff = diff + TimeSpan.FromDays(1);
}
What you need is to use the DateTime classs Subtract method, which returns a TimeSpan.
var dateOne = DateTime.Now;
var dateTwo = DateTime.Now.AddMinutes(-5);
var diff = dateTwo.Subtract(dateOne);
var res = String.Format("{0}:{1}:{2}", diff.Hours,diff.Minutes,diff.Seconds));
The way I usually do it is subtracting the two DateTime and this gets me a TimeSpan that will tell me the diff.
Here's an example:
DateTime start = DateTime.Now;
// Do some work
TimeSpan timeDiff = DateTime.Now - start;
timeDiff.TotalMilliseconds;
IF they are both UTC date-time values you can do TimeSpan diff = dateTime1 - dateTime2;
Otherwise your chance of getting the correct answer in every single possible case is zero.
var startDate = new DateTime(2007, 3, 24);
var endDate = new DateTime(2009, 6, 26);
var dateDiff = endDate.Subtract(startDate);
var date = string.Format("{0} years {1} months {2} days", (int)dateDiff.TotalDays / 365,
(int)(dateDiff.TotalDays % 365) / 30, (int)(dateDiff.TotalDays % 365) / 30);
Console.WriteLine(date);
private void button1_Click(object sender, EventArgs e)
{
TimeSpan timespan;
timespan = dateTimePicker2.Value - dateTimePicker1.Value;
int timeDifference = timespan.Days;
MessageBox.Show(timeDifference.ToString());
}
You can use in following manner to achieve difference between two Datetime Object. Suppose there are DateTime objects dt1 and dt2 then the code.
TimeSpan diff = dt2.Subtract(dt1);
You need to use a TimeSpan. Here is some sample code:
TimeSpan sincelast = TimeSpan.FromTicks(DateTime.Now.Ticks - LastUpdate.Ticks);
This question already has answers here:
C#: how do I subtract two dates?
(11 answers)
Closed 10 years ago.
i want to subtract previous date from current date. previous date may be 2 months and 15 days or 1 year 9 month and 10 days... like this etc... So please how can i write the Coding in C#. thanks a lot.
Any answer using TimeSpan will not be able to give you "2 months and 15 days" - as the length of a month changes over time.
Doing this using the base class libraries is a pain... which is one of the reasons I started the Noda Time project. Amongst its other features, it allows you to determine the Period between to dates (or dates and times, etc).
For example, let's see how long I've been on Stack Overflow:
LocalDate today = new LocalDate(2013, 2, 8);
LocalDate start = new LocalDate(2008, 9, 26);
// This defaults to using year, month, day units. You can specify alternatives.
Period period = Period.Between(start, today);
Console.WriteLine("{0} years; {1} months; {2} days",
period.Years, period.Months, period.Days);
Output:
4 years; 4 months; 13 days
Or if you actually wanted to subtract a period from a date (the question isn't very clear) you can do that too:
Period period = new PeriodBuilder { Years = 4, Months = 4, Days = 13 }.Build();
LocalDate today = new LocalDate(2013, 2, 8);
LocalDate start = today - period;
Console.WriteLine(start);
Output:
25 September 2008
Note that this doesn't give September 26th, because of the somewhat crazy nature of date/time arithmetic. If you added the period to September 26th you'd get today... but that's not the same thing. Treat this as a warning that you need to be really careful about describing what you want to achieve :)
This second side you can do with the BCL fairly easily though:
DateTime today = new DateTime(2013, 2, 8);
DateTime start = today.PlusYears(-4).PlusMonths(-4).PlusDays(-13);
There's no BCL type to represent that "years, months, days" value though.
Your question is a little confusing. Do you want to subtract one date from another date, or do you want to subtract a period of time from a date.
1. Subtract one date from another date:
DateTime previousDate = new DateTime(1990, 12, 12);
DateTime currentDate = DateTime.UtcNow;
TimeSpan difference = currentDate - previousDate;
You can then use the TimeSpan methods to get the difference in various units of time as you like.
Here's more info on TimeSpan: http://msdn.microsoft.com/en-us/library/system.timespan.aspx
2. Subtract a period of time from a date
DateTime currentDate = DateTime.UtcNow;
TimeSpan periodOfTime = new TimeSpan(12, 12, 0, 0);
DateTime newDate = currentDate - periodOfTime;
However, you'll have to calculate yourself what the length of a month is, if that's what you want.
You can use DateTime.Subtract.
Examples from article:
System.DateTime date1 = new System.DateTime(1996, 6, 3, 22, 15, 0);
System.DateTime date2 = new System.DateTime(1996, 12, 6, 13, 2, 0);
System.DateTime date3 = new System.DateTime(1996, 10, 12, 8, 42, 0);
// diff1 gets 185 days, 14 hours, and 47 minutes.
System.TimeSpan diff1 = date2.Subtract(date1);
// date4 gets 4/9/1996 5:55:00 PM.
System.DateTime date4 = date3.Subtract(diff1);
// diff2 gets 55 days 4 hours and 20 minutes.
System.TimeSpan diff2 = date2 - date3;
// date5 gets 4/9/1996 5:55:00 PM.
System.DateTime date5 = date1 - diff2;
TimeSpan timeSpan = new TimeSpan(2,2,0);
DateTime dateTime = DateTime.Now.Subtract(timeSpan);
When you subtract two date in C# you get a TimeSpan object.
You can acces different properties of it to get the actual days, hours, minutes etc. taht it represents:
DateTime a;
DateTime b;
//assign some values
TimeSpan span = a.Subtract(b);
Console.WriteLine("Days: " + span.Days);
The following should do.
TimeSpan diff = DateTime.Now - previousDate;
I want to get a Timespan structure which represent a year in C#.
The tricky thing is that what a year is, depends on where it starts.
You can do
DateTime now = DateTime.Now;
TimeSpan span = now.AddYears(1) - now;
This would give you the 1 year timespan from the current moment to one year later
The key question here is: which year?
The length of the timespan obviously depends on whether the year you want is a leap year or not and when it starts.
If you want one year starting from today go with #sehe's answer.
If you want the current year go with #Oyvind,
If you want a reasonable approximation you can go with #Nayan, or for a 365.25 approximation use:
TimeSpan oneYearSpan = new TimeSpan(365, 6, 0, 0);
You can't, as a year doesn't have a fixed length (is it 365 or 366 days or about 365.25?). That's also why you can't have a month as TimeSpan (28, 29, 30, 31 days??)
Rough example:
TimeSpan oneYearSpan = new TimeSpan(365, 0, 0, 0);
Will this do?
DateTime intialDate = Date.Now.Date;
TimeSpan yearSpan = intialDate.AddYears(1).Subtract(intialDate)
As other peoplehave mentioned you may want to consider leap years. In that case you can intiate intialDate accordingly.
If you want to be pretty accurate you could use the number of nano seconds in a year.
I think that this moves by 0.5 seconds every century, so should be good for a long while yet!
public TimeSpan MyYear
{
get
{
// Year = 3.1556926 × 10^16 nanoseconds
return new TimeSpan(31556926000000000);
}
}
There are already some good answers on this page, this is just another option.
It depends on which year you want to represent, since not all years are of equal length.
This is the way to find the length of 2010 for example:
var timestamp = new DateTime(2011, 1, 1) - new DateTime(2010, 1, 1);
Change the year in the DateTimes to find the length of the year you want.
Here's how to do this, utilizing the IsLeapYear to determain number of day.
int span = DateTime.IsLeapYear(1996) ? 366: 365;
var year1996 = new TimeSpan(span, 0, 0, 0);
I have an ASP.NET, VB.NET Date, and I'm trying to get the number of milliseconds since January 1st, 1970. I tried looking for a method in MSDN, but I couldn't find anything. Does anyone know how to do this?
Starting with .NET 4.6, The method ToUnixTimeMilliseconds provides a more accurate solution.
From DateTimeOffset:
DateTimeOffset.Now.ToUnixTimeMilliseconds()
From DateTime:
new DateTimeOffset(dateTime).ToUnixTimeMilliseconds()
Source: https://learn.microsoft.com/en-us/dotnet/api/system.datetimeoffset.tounixtimemilliseconds?view=netframework-4.6#System_DateTimeOffset_ToUnixTimeMilliseconds
You can subtract any two DateTime instances and get TimeSpan and TotalMilliseconds would give you total milliseconds. Sample below.
DateTime dt1970 = new DateTime(1970, 1, 1);
DateTime current = DateTime.Now;//DateTime.UtcNow for unix timestamp
TimeSpan span = current - dt1970;
Console.WriteLine(span.TotalMilliseconds.ToString());
one liner
//DateTime.MinValue is 01/01/01 00:00 so add 1969 years. to get 1/1/1970
DateTime.Now.Subtract(DateTime.MinValue.AddYears(1969)).TotalMilliseconds;
Alternatively, you can use the Ticks property and avoid construction of a temporary object:
long epochTime = (DateTime.UtcNow.Ticks - 621355968000000000) / 10000;
However, this isn't entirely
Reasoning:
DateTime d = new DateTime(1970, 01, 01);
var temp = d.Ticks; // == 621355968000000000
This will provide the UNIX Epoch in milliseconds.
(Respects UTC time instead of your local time)
Split(DateTime.UtcNow.Subtract(DateTime.MinValue.AddYears(1969)).TotalMilliseconds(), ".", 2)(0)
How can I find difference between two time intervals.
Like 13:45:26.836 - 14:24:18.473 which is of the format "Hour:Min:Sec:Millisecs". Now i need to find the time difference between these two times.
How can i do this in C#.?
Thanks in advance.
Basically, what you need to do is put those time values into DateTime structures. Once you have your two DateTime variables, just subtract them from one another - the result is a variable of type TimeSpan:
DateTime dt1 = new DateTime(2010, 5, 7, 13, 45, 26, 836);
DateTime dt2 = new DateTime(2010, 5, 7, 14, 24, 18, 473);
TimeSpan result = dt2 - dt1;
string result2 = result.ToString();
TimeSpan has a ton of properties that get sets - the difference in all sorts of units, e.g. milliseconds, seconds, minutes etc. You can also just do a .ToString() on it to get a string representation of the result. In result2, you'll get something like this:
00:38:51.6370000
Is that what you're looking for?
i'm posting an example;
you can check it and adapt your program,
/* Read the initial time. */
DateTime startTime = DateTime.Now;
Console.WriteLine(startTime);
/* Do something that takes up some time. For example sleep for 1.7 seconds. */
Thread.Sleep(1700);
/* Read the end time. */
DateTime stopTime = DateTime.Now;
Console.WriteLine(stopTime);
/* Compute the duration between the initial and the end time.
* Print out the number of elapsed hours, minutes, seconds and milliseconds. */
TimeSpan duration = stopTime - startTime;
Console.WriteLine("hours:" + duration.Hours);
Console.WriteLine("minutes:" + duration.Minutes);
Console.WriteLine("seconds:" + duration.Seconds);
Console.WriteLine("milliseconds:" + duration.Milliseconds);
Find the number of seconds; subtract both numbers and then you can figure out the time difference. Depending on the programming language you use, I am positive their must be a library that can handle it.
//Start off with a string
string time1s = "13:45:26.836";
string time2s = "14:24:18.473";
TimeSpan interval = DateTime.Parse(time2s) - DateTime.Parse(time1s);
This will produce a result of:
Days 0 int Hours 0 int
Milliseconds 637 int
Minutes 38 int Seconds 51 int
Ticks 23316370000 long
TotalDays 0.02698653935185185 double
TotalHours 0.64767694444444446 double
TotalMilliseconds 2331637.0 double
TotalMinutes 38.860616666666665 double
TotalSeconds 2331.6369999999997 double