Solved

SIMPLE: time variable?

Posted on 2002-04-18
5
266 Views
Last Modified: 2010-04-02
is there a variable or structure that I could use to hold a simulated time? I'm working on a simulation program and I need to handle time. I'm looking for a way to increment the time in minutes and have it roll over to hours.

So if i incremented a time variable by 30 minutes 3 times. It could from 12:00 to 1:30. Can someone tell me how to do this thanks.
0
Comment
Question by:llllllllll
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 2
5 Comments
 
LVL 1

Expert Comment

by:lsmgms
ID: 6952659
Hi,

How about this:
  struct tm
  time_t mktime( struct tm *timeptr );



Example quoted from MSDN:

/* MKTIME.C: The example takes a number of days
 * as input and returns the time, the current
 * date, and the specified number of days.
 */

#include <time.h>
#include <stdio.h>

void main( void )
{
   struct tm when;
   time_t now, result;
   int    days;

   time( &now );
   when = *localtime( &now );
   printf( "Current time is %s\n", asctime( &when ) );
   printf( "How many days to look ahead: " );
   scanf( "%d", &days );

   when.tm_mday = when.tm_mday + days;
   if( (result = mktime( &when )) != (time_t)-1 )
      printf( "In %d days the time will be %s\n",
              days, asctime( &when ) );
   else
      perror( "mktime failed" );
}


Output

Current time is Tue May 03 12:45:47 1994

How many days to look ahead: 29
In 29 days the time will be Wed Jun 01 12:45:47 1994


Hope this will help.
0
 

Author Comment

by:llllllllll
ID: 6952676
ok how would i set that to a specific time (instead of current time)
0
 
LVL 1

Expert Comment

by:lsmgms
ID: 6952718
Using your example:
So if i incremented a time variable by 30 minutes 3 times. It could from 12:00 to 1:30.

#include <time.h>
#include <stdio.h>
void main(void)
{
  struct tm when;
  time_t now, result;

     /* simply initialize to localtime */
  time( &now );
  when = *localtime( &now );

     /* set your time now, assume you do not need day info */
     when.tm_hour = 12;
     when.tm_min = 0;
     when.tm_sec = 0;
     
     printf("Org time %02d:%02d;%02d\n", when.tm_hour, when.tm_min, when.tm_sec);

     /* add 30 * 3 min */
     when.tm_min = 90;
  if( (result = mktime( &when )) != (time_t)-1 )
          printf("New time %02d:%02d;%02d\n", when.tm_hour, when.tm_min, when.tm_sec);

     /* output */
     /*
          Org time 12:00;00
          New time 13:30;00
     */


}



0
 

Author Comment

by:llllllllll
ID: 6952749
can i do that on 12 hour time?
0
 
LVL 1

Accepted Solution

by:
lsmgms earned 100 total points
ID: 6952760
There is not different for the data stored in the structure.  It is how you present your data.  Example, bu changing the code from:
if( (result = mktime( &when )) != (time_t)-1 )
         printf("New time %02d:%02d;%02d\n", when.tm_hour, when.tm_min, when.tm_sec);


to
  if( (result = mktime( &when )) != (time_t)-1 )
          printf("New time %02d:%02d:%02d %s\n",
          (when.tm_hour>12 ? when.tm_hour-12: when.tm_hour),
          when.tm_min,
          when.tm_sec,
          (when.tm_hour>12 ? "pm": "am"));

-->New time 01:30:00 pm

You will get your "12 hour time"


0

Featured Post

VIDEO: THE CONCERTO CLOUD FOR HEALTHCARE

Modern healthcare requires a modern cloud. View this brief video to understand how the Concerto Cloud for Healthcare can help your organization.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

What is C++ STL?: STL stands for Standard Template Library and is a part of standard C++ libraries. It contains many useful data structures (containers) and algorithms, which can spare you a lot of the time. Today we will look at the STL Vector. …
Basic understanding on "OO- Object Orientation" is needed for designing a logical solution to solve a problem. Basic OOAD is a prerequisite for a coder to ensure that they follow the basic design of OO. This would help developers to understand the b…
The goal of the video will be to teach the user the concept of local variables and scope. An example of a locally defined variable will be given as well as an explanation of what scope is in C++. The local variable and concept of scope will be relat…
The goal of the video will be to teach the user the difference and consequence of passing data by value vs passing data by reference in C++. An example of passing data by value as well as an example of passing data by reference will be be given. Bot…

623 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question