The C++ standard library doesn't provide any proper date type. C++ inherits the structs and functions for date and time manipulation from the C language. To access date and time related functions and structures, you have to use/include a header file in your C++ program named time.h.
There are four time-related types: clock_t, time_t, size_t, and tm. The types clock_t, size_t and time_t are capable of representing the system time and date as some sort of integer.
The structure type tm holds the date and time in the form of a C structure having the elements given here in these statements:
struct tm
{
int tm_sec; // seconds of minutes from 0 to 61
int tm_min; // minutes of hour from 0 to 59
int tm_hour; // hours of day from 0 to 24
int tm_mday; // day of month from 1 to 31
int tm_mon; // month of year from 0 to 11
int tm_year; // year since 1900
int tm_wday; // days since Sunday
int tm_yday; // days since January 1st
int tm_isdst; // hours of daylight savings time
}
The tm structure is very important when working with the date and time in either C or C++ language. This structure holds the date and time in the form of a C structure. Most of the time related functions makes use of tm structure. Let's take some examples on date and time in C++ for complete understanding on C++ date and time.
This C++ program simply prints the local and UTC date and time on the screen.
/* C+ Date and Time - Example Program of C++ Date and Time
* This program prints local date and time, UTC date and
* time on the output screen */
#include<iostream.h>
#include<conio.h>
#include<time.h>
void main()
{
clrscr();
time_t now = time(0); // current system date/time
char* dt = ctime(&now); // convert in string form
cout<<"Local date and time is:-\n\t\t"<<dt<<"\n";
tm *gmtm = gmtime(&now); // converting now to tm struct for UTC date/time
dt = asctime(gmtm);
cout<<"UTC date and time is:-\n\t\t"<<dt;
getch();
}
Here is the sample output of the above C++ program:
This C++ program prints the current or today's date on the output screen.
/* C++ Date and Time - Example Program of C++ Date and Time
* This program prints today's date on the output screen */
#include<iostream.h>
#include<conio.h>
#include<time.h>
void main()
{
clrscr();
time_t now = time(0);
tm *ltm = localtime(&now);
cout<<"Today is ";
cout<<ltm->tm_mday<<"/"<<1+ltm->tm_mon<<"/";
cout<<1900+ltm->tm_year<<"\n";
getch();
}
Here is the sample output of this C++ program:
This C++ program prints the current time on the output screen.
/* C++ Date and Time - Example of C++ Date and Time
* This program prints current date on the output
* output screen in C++ */
#include<iostream.h>
#include<conio.h>
#include<time.h>
void main()
{
clrscr();
time_t now = time(0);
tm *ltm = localtime(&now);
cout<<"The current time is ";
cout<<1+ltm->tm_hour<<":";
cout<<1+ltm->tm_min<<":";
cout<<1+ltm->tm_sec<<"\n";
getch();
}
Below is the sample run of the above C++ program:
This is the complete version of the date and time programs (as shown above) in C++.
/* C++ Date and Time - Example of C++ Date and Time
* This program demonstrates the working of date
* and time in C++ program */
#include<iostream.h>
#include<conio.h>
#include<stdlib.h>
#include<time.h>
void main()
{
clrscr();
char choice, ans;
time_t now = time(0);
tm *ltm = localtime(&now);
do
{
cout<<"1. Time\n";
cout<<"2. Date\n";
cout<<"3. Month\n";
cout<<"4. Year\n";
cout<<"5. All\n";
cout<<"6. Exit\n";
cout<<"\nEnter your choice (1-6) ";
cin>>choice;
clrscr();
switch(choice)
{
case '1':
cout<<"The current time is ";
cout<<1+ltm->tm_hour<<":";
cout<<1+ltm->tm_min<<":";
cout<<1+ltm->tm_sec<<"\n";
break;
case '2':
cout<<"Today's date is ";
cout<<ltm->tm_mday<<"\n";
break;
case '3':
cout<<"It's ";
cout<<1+ltm->tm_mon<<"th month\n";
break;
case '4':
cout<<"This is ";
cout<<1900+ltm->tm_year<<"\n";
break;
case '5':
cout<<"Time: "<<1+ltm->tm_hour<<":";
cout<<1+ltm->tm_min<<":";
cout<<1+ltm->tm_sec<<"\n";
cout<<"Date: "<<ltm->tm_mday<<"\n";
cout<<"Month: "<<1+ltm->tm_mon<<"\n";
cout<<"Year: "<<1900+ltm->tm_year<<"\n";
break;
case '6':
exit(1);
default:
cout<<"Wrong choice..!!..Press a key to exit..\n";
getch();
exit(2);
}
cout<<"\nWant to check more ? (y/n).. ";
cin>>ans;
cout<<"\n";
}while(ans=='y' || ans=='Y');
getch();
}
Here are some sample runs of the above C++ program:
