In this article, we are
going to look at how to calculate the date difference between two dates in C#.
Like in other OOP languages, C# has two data types to store the results.
- DateTime Structure
- TimeSpan Structure
DateTime
Struct
DateTime Structure is a
child of System namespace and no any
other external libraries needed for this. Normally DateTime constructor takes
minimum 3 parameters; year, month and date. Further, the constructor can be
overloaded with multiple parameters to get the time range. To take the date and
time ranges, we can use Calendar data type as well. But it is recommended to
use DateTime struct, as it is the most efficient and accurate way.
/*
Year=2019 Month=03 Date=01*/
DateTime datetime = new DateTime(2019, 03, 01);
/* Year=2019 Month=03 Date=01 Hour=00 Minute=00
Second=00*/
DateTime datetime = new DateTime(2019, 03, 01, 00, 00, 00);
TimeSpan
Struct
TimeSpan is considered as
the data type which is used to store the length of time. Just like the DateTime
struct, it is also implemented as a struct and has several overloaded
constructors. TimeSpan Structure too is a child of System namespace and in our example, we are going to use it to
store the difference between the dates. Hence, TimeSpan can be used for many
date manipulations as shown below.
TimeSpan
days = TimeSpan.FromDays(1);
TimeSpan hours = TimeSpan.FromHours(1);
TimeSpan mins = TimeSpan.FromMinutes(1);
Console.WriteLine(days);
Console.WriteLine(hours);
Console.WriteLine(mins);
What
is a Struct?
Unlike classes, structs
can be used without instantiating with a new keyword. Structs provide better
performance when the value-type collection to be grouped is small. Structs
cannot inherit either from the same struct type or even a different class. To
define a struct, we need to use the word struct
before the name of the class.
public struct Employee {
public int age;
public setAge(int newAge)
{
age
= newAge;
}
}
In this
example, we are calculating the difference between the dates using 2 methods.
·
Date Difference by Subtract()
Method
·
Date Difference by
Subtraction(-) Operator
Date Difference by Subtract() Method
DateTime structure
has its own predefined method Subtract() which takes a date as the argument and
returns the difference between the specified dates. It results in TimeSpan
value and we can use different properties defined by the TimeSpan to display
the output as per our requirement.
class DateDifference
{
public void getDateDiff(DateTime date1, DateTime date2) {
DateTime oldDate = new System.DateTime(date1.Year,
date1.Month,
date1.Day, date1.Hour, date1.Minute, date1.Second);
DateTime newDate = new System.DateTime(date2.Year,
date2.Month,
date2.Day, date2.Hour, date2.Minute, date2.Second);
TimeSpan dateDiff =
newDate.Subtract(oldDate); //using substraction
method
Console.WriteLine($"Date Difference is = {dateDiff.Days}");
}
static void main(string[] args)
{
DateTime date1 = new System.DateTime(2019, 3, 1, 12, 0,
0);
DateTime date2 = new System.DateTime(2019, 3, 2, 13, 0,
0);
DateDifference
dateDifference = new DateDifference();
dateDifference.getDateDiff(date1, date2); //output->
1
}
}
In here we
are using only the Days property of the TimeSpan structure. Nevertheless, there
are many other properties like Hours, Minutes, Seconds, TotalDays etc.
Date Difference by Subtraction (-) Operator
The easier
way of finding the date difference is by using the minus operator. In the below
example, we’ll be creating a method called getDateDiff() and passes two
DateTime arguments to it. From the passed arguments; Year, Minutes, Seconds
etc. are extracted and passed to the constructor. Finally, getDateDiff() method
is invoked in the main method using the values of the user. This method too results
in the same output as the Subtract() method.
class DateDifference
{
public void getDateDiff(DateTime date1, DateTime date2) {
DateTime oldDate = new System.DateTime(date1.Year,
date1.Month,
date1.Day, date1.Hour, date1.Minute, date1.Second);
DateTime newDate = new System.DateTime(date2.Year,
date2.Month,
date2.Day, date2.Hour, date2.Minute, date2.Second);
TimeSpan dateDiff = newDate - oldDate; //using substraction operator
Console.WriteLine($"Date Difference is = {dateDiff.Days}");
}
static void main(string[] args)
{
DateTime date1 = new System.DateTime(2019, 3, 1, 12, 0,
0);
DateTime date2 = new System.DateTime(2019, 3, 2, 13, 0,
0);
DateDifference
dateDifference = new DateDifference();
dateDifference.getDateDiff(date1, date2); //output->
1
}
}
Apart from
the previously stated 2 methods, VB.NET namespace provides DateDiff() function
to calculate date difference between two dates. For that, we need to add the VB
script to the C# project and it is not recommended to practice in C#
environment. So far we have calculated the date difference using two methods,
but one of the important points to be noticed is that, both the dates we used are
considered to be in the same time zone. What
happens if the dates are in different time zones? For that, we can format
our final output as follows.
TimeSpan
withTimezones = newDate.ToUniversalTime().Subtract(oldDate.ToUniversalTime());
By using
ToUniversalTime() method, we are converting the two values into a common time
zone before subtraction, so that no any other confusion occur during the
conversion.
