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Get the days of year and all the hours between 2 dates in C#

I have folder structures like Year (2016)->day of year (308,309) -> hour in the day (00 to 23). I want to know how to get all the days and hours between 2 dates say between today 9am and yesterday 10am. Is there an easy way to do this?
My bad! I didn't give enough information. So I did try Span before I asked this and I don't want to get the different like the span.days, hours or mins instead i want the days of the year and hours between 2 dates.
like between yesterday 10 am and today it will 307th day 10th hour,11th hour and so on... until today 308th day and 9th hour. I can do this by looping thru the dates but i wanted to know if there is a straight forward way.

I would create a simple class for storing the data you need:
class DateInfo
{
public string Year {get;set;}
public string DayOfYear{get;set;}
public string Hour {get;set;}
}
and then get the results:
DateTime d1 = DateTime.Today.AddDays(-1).AddHours(10);
DateTime d2 = DateTime.Today.AddHours(9);
IList<DateInfo> dates = new List<DateInfo>();
while (d1 <= d2)
{
DateInfo dateInfo = new DateInfo()
{
Year = d1.ToString("yyyy"),
DayOfYear = d1.DayOfYear.ToString(),
Hour = d1.ToString("HH"),
};
dates.Add(dateInfo);
d1 = d1.AddHours(1);
}

There would be n number of ways to find out the difference between two dates. 2 of them are as follows
DateTime a = new DateTime(2016, 11, 03, 10, 00, 00);
DateTime b = DateTime.Now;
Console.WriteLine(b.Subtract(a).TotalHours);
This will give you the total hours between two dates Where as
TimeSpan span = (b - a);
Console.WriteLine(String.Format("{0} days, {1} hours, {2} minutes, {3} seconds", span.Days, span.Hours, span.Minutes, span.Seconds));
This will give you the details in the format which everyone can understand.

How do i get the minutes part when i subtract two time values

I want minutes part when i subtract two time values.
I am subtracting current time with 11:30 PM and the result i need in minutes.
I am trying the following code in c#.
TimeSpan eTs = new TimeSpan(23, 30, 00);
int min = System.DateTime.Now.Minute - eTs.Minutes;
but its giving wrong values.
Any help?
Thanks in advance.

It gives wrong value because you are substracting ints. It could even give negative numbers. You should substract the TimeSpan from the DateTime, which gives you another DateTime and use it's Minute property.
var eTs = new TimeSpan(23, 30, 00);
var min = (System.DateTime.Now - eTs).Minute;
EDIT
I am subtracting current time with 11:30 PM and the result i need in
minutes.
No, you are substracting 23 hours and 30 minutes from the current date time.
If you want to know how much minutes have passed since 11:30 PM (what day/month/year), you should:
var min = (System.DateTime.Now - somePastDate).TotalMinutes; //somePastDate must be a DateTime

Do you wanna subtract 2 dateTime and Get the total in minutes try this:
DateTime data = DateTime.Now;
DateTime data2 = DateTime.Now.AddDays(-2);
TimeSpan sub = data - data2;
Console.WriteLine(sub.TotalMinutes);
Or If you wanna subtract minutes from a datetime try this
TimeSpan eTs = new TimeSpan(23, 30, 00);
DateTime data2 = System.DateTime.Now.AddMinutes(-eTs.TotalMinutes);
Console.WriteLine(data2);

Difference between two times C# [duplicate]

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);

c# date comparison returning a DateTime object

Given a DateTime object (last purchase) can I compare against DateTime.Now to return a new DateTime object that contains, years, months, days, hours and seconds?
I can compare dates and return the number of years however, I need all details down to the second.
Any help or examples would be appreciated

You don't want to have a new DateTime object. What you want to have is a TimeSpan. And that's what you get if you subtract DateTime instances:
TimeSpan difference = DateTime.Now - yourDate

No, you can't, because a DateTime represents an absolute point in time, not a span of time. The correct object to use for the difference is TimeSpan. It has properties for all the relevant time units. You can get one by just subtracting two DateTimes:
TimeSpan ts = DateTime.Now - purchaseDate;

You can use the TimeSpan to compare two dates. Have a look at
DateTime date1 = new DateTime(2010, 1, 1, 8, 0, 15);
DateTime date2 = new DateTime(2010, 8, 18, 13, 30, 30);
// Calculate the interval between the two dates.
TimeSpan interval = date2 - date1;
Years and months have to be calculated through custom coding as month is a variable unit of measure but since TimeSpan tell you the days you can calculate months and years yourself.
Have a look at this post.
Have a look at this forum.
Hope this help.

TimeSpan is the correct way to handle this, however, if you don't want to do the conversion of months/years yourself, you can always use some recursive method to subtract years until you get to the correct year, months until you get to the correct month, days until you get to the correct day, etc. It would suck and be ugly, though.
Also, you'd need a custom object that would hold the data for you.
A rough cut would be something like
DateTime original = [Whatever]
DateTime compare = [Whatever]
DateTimeDiff difference = GetDifference(original, compare)
GetDifference(DateTime original, DateTime compare)
{
DateTimeDiff difference = new DateTimeDifference
while(!original.Equals(compare) && original.Year >= compare.Year)
{
original.AddYears(-1);
difference.Years++;
}
<snip... //more code to do the same thing for months, days, hours, etc.)
}
Like I said, it would suck and be ugly, but you could do it.

This library includes the class DateDiff with support of Year and Months:
// ----------------------------------------------------------------------
public void DateDiffSample()
{
DateTime date1 = new DateTime( 2009, 11, 8, 7, 13, 59 );
Console.WriteLine( "Date1: {0}", date1 );
// > Date1: 08.11.2009 07:13:59
DateTime date2 = new DateTime( 2011, 3, 20, 19, 55, 28 );
Console.WriteLine( "Date2: {0}", date2 );
// > Date2: 20.03.2011 19:55:28
DateDiff dateDiff = new DateDiff( date1, date2 );
// differences
Console.WriteLine( "DateDiff.Years: {0}", dateDiff.Years );
// > DateDiff.Years: 1
Console.WriteLine( "DateDiff.Quarters: {0}", dateDiff.Quarters );
// > DateDiff.Quarters: 5
Console.WriteLine( "DateDiff.Months: {0}", dateDiff.Months );
// > DateDiff.Months: 16
Console.WriteLine( "DateDiff.Weeks: {0}", dateDiff.Weeks );
// > DateDiff.Weeks: 70
Console.WriteLine( "DateDiff.Days: {0}", dateDiff.Days );
// > DateDiff.Days: 497
Console.WriteLine( "DateDiff.Weekdays: {0}", dateDiff.Weekdays );
// > DateDiff.Weekdays: 71
Console.WriteLine( "DateDiff.Hours: {0}", dateDiff.Hours );
// > DateDiff.Hours: 11940
Console.WriteLine( "DateDiff.Minutes: {0}", dateDiff.Minutes );
// > DateDiff.Minutes: 716441
Console.WriteLine( "DateDiff.Seconds: {0}", dateDiff.Seconds );
// > DateDiff.Seconds: 42986489
} // DateDiffSample

If you want years and months you have to write your own code. It's actually tricky to write this code with an output which is 100% correct due to the different leapyear issues.
Here are a couple of tricky special cases (Note 2012 is a leap year, 2011 isn't):
Between February 28th 2010 and February 28th 2011 - it is 1y, 0m, 0d
Between February 28th 2011 and February 28th 2012 - it is 1y, 11m, 28d
Between February 28th 2011 and February 29th 2012 - it is 1y, 0m, 0d
Between February 29th 2012 and February 28th 2013 - it is 1y, 0m, 0d
Between February 10th 2011 and March 9th 2011 - it is 0y, 0m, 27d
Between February 10th 2012 and March 9th 2012 - it is 0y, 0m, 28d
I think you need to implement something like AllenG's algorithm with a few modifications
You need to start with the earliest datetime (datetime1). Make sure that it is earliest.
Loop until datetime1.AddYears(1) compares as greater than or equal to your latest datetime (datetime2). Make sure to compare the entire datetimes and not just the year property of starttime and endttime.
Increment a year counter on each iteration.
actually add a year to your datetime1 copy.
Start with the datetime1 copy (to which you have added years in step 2)
Loop until datetime1.AddMonths(1) compares as greater than or equal to your latest datetime (datetime2). Again: Make sure you compare the entire datetimes and not just the month component.
Increment a month counter on each iteration.
actually add a month to your datetime1 copy.
etc. etc
This algorithm ensures that you are calculating your years, months, days, hours, minutes and seconds differences using the right excerpt of the underlying calendar.

I think you need to combine the TimeSpan and some custom calculations. This, because you would like the years and months, which have a variable length. In addition you also want the number of hours, minutes and seconds.
I think this approach would serve your needs:
var date1 = new DateTime(2010, 1, 1, 8, 0, 15);
var date2 = new DateTime(2007, 8, 18, 13, 30, 30);
var differenceYears = date1.Year - date2.Year;
var tempDate = date2.AddYears(differenceYears);
var differenceMonths = date1.Month - tempDate.Month;
if (differenceMonths < 0)
{
differenceMonths += 12;
differenceYears--;
}
tempDate = date2.AddYears(differenceYears).AddMonths(differenceMonths);
var additionalTimeSpan = date1 - tempDate;
var differenceDays = additionalTimeSpan.Days;
var differenceHours = additionalTimeSpan.Hours;
var differenceMinutes = additionalTimeSpan.Minutes;
var differenceSeconds = additionalTimeSpan.Seconds;

subtract 2 datetime fields to get the days left difference

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)