find how many hours in a given timespan

[Zaynt]

Hi,

 

I was wondering how I can find out how many hours there is in the timespan eg. 12pm - 4pm when the only information I have is a starting time and a stop time.

 

example:

 

start: 8am

stop: 1pm

 

there is 1 hour in the timspan 12pm - 4pm.

 

Anyone know how I make a script that can calculate this in php?

[mindspin311]

Well converting to 24 hour military time is where you want to be. Just do 24 our time and it's just simple subtraction, or you can use the function explode to separate a string.

 

$time = '8 am';
$military_time = expode(' ', $time);

 

Now all you do is.

 

if ($military_time[1] == 'pm')
{
  $newtime = $military_time[0] + 12;
}
else
{
  $newtime = $military_time[0];
}

[mindspin311]

Oh.. and also you want to check if start time is greater than stop time. If it is, then stop time is the next day, and we just add another 24 to stop time, then subtract.

 

Sorry.. it won't let me edit my post for some reason.

[Zaynt]

actually I have the starting time and end-time in unix timestamp format...what would the code look like then ?

 

my timestamp both start and stop time is in this format:

mktime(h,m,s ,month, day,year);

[laffin]

<?php

  $cst="8am"; // Clock Start Time

  $cet="3pm"; // Clock End Time

  $start = strtotime($cst); // Convert to unix timestamp

  $end = strtotime($cet);

 

  $end+=($end<$start) ?(60*60*24):0; // add 1 day if $end is < $start

  $timespan=(($end-$start)/60)/60;

  echo "$cst - $cet = $timespan hrs.";

?>

 

[Zaynt]

ok...I guess the topic title is a bit misleading. You see I don't just want to output hours in a timespan....I want to output how many hours are within a given timespan in a timespan. It's hard to explain but if you watch my example carefully maybe you'll see:

 

I have a start-time: eg. 7am

 

I have a end-time : eg. 3pm

 

how many hours in the timespan above are between 12pm and 4pm? the answer is 3 hours(12pm-3pm) in this case...see?

 

now how can I calculate this in php?

[laffin]

 

the timespan between 12pm and 4pm is 4 hrs

12-1

1-2

2-3

3-4

 

how do u get 3 hrs?

 

[Zaynt]

only 3 hours of the timespan 7am - 3pm is within the timespan 12pm - 4pm....see?

[laffin]

than add some if checking to start and end times (using unix timestamps)

adjusting the start and end times

 

 

[Zaynt]

Can you give me an example? I'm pretty new at this an I don't know where to start with the if-statements..

 

lets use this as a starting point:

 

start-time = 07:00

 

end-time = 15:00

 

how many hours in that timespan are between 12:00 and 16:00?

[laffin]

if u followed the code givin

and use if statements to limit hrs, it's not hard

<?php

  $tcst="7am"; // Timespan Clock Start Time

  $tcet="3pm"; // Timespan Clock End Time

  $tstart = strtotime($tcst); // Convert to unix timestamp

  $tend = strtotime($tcet);

  $cst="12pm"; // Clock Start Time

  $cet="4pm"; // Clock End Time

  $start = strtotime($cst); // Convert to unix timestamp

  $end = strtotime($cet);

 

 

  $end+=($end<$start) ?(60*60*24):0; // add 1 day if $end is < $start

  $tend+=($tend<$tstart) ?(60*60*24):0; // add 1 day if $tend is < $start for timespan

 

  $start=($start<$tstart)?$tstart:$start; // change start time to timespan if earliear

  $end=($end>$tend)?$tend:$send; // change end time to timespan if later

 

  $timespan=(($end-$start)/60)/60;

  echo "$cst - $cet = $timespan hrs.";

?>

[haku]

laffin you've been around enough to know to use code tags around your code.

[Zaynt]

if u followed the code givin

and use if statements to limit hrs, it's not hard

<?php

  $tcst="7am"; // Timespan Clock Start Time

  $tcet="3pm"; // Timespan Clock End Time

  $tstart = strtotime($tcst); // Convert to unix timestamp

  $tend = strtotime($tcet);

  $cst="12pm"; // Clock Start Time

  $cet="4pm"; // Clock End Time

  $start = strtotime($cst); // Convert to unix timestamp

  $end = strtotime($cet);

 

 

  $end+=($end<$start) ?(60*60*24):0; // add 1 day if $end is < $start

  $tend+=($tend<$tstart) ?(60*60*24):0; // add 1 day if $tend is < $start for timespan

 

  $start=($start<$tstart)?$tstart:$start; // change start time to timespan if earliear

  $end=($end>$tend)?$tend:$send; // change end time to timespan if later

 

  $timespan=(($end-$start)/60)/60;

  echo "$cst - $cet = $timespan hrs.";

?>

 

It's been a while, but i tried your code and it worked fine but when the "Timespan Clock Start Time" and "Timespan Clock End Time" were the same as  "Clock Start Time" and "Clock End Time" i got thousands of hours, when it should have been 4.