473,224 Members | 1,657 Online
Bytes | Software Development & Data Engineering Community
Post Job

Home Posts Topics Members FAQ

Join Bytes to post your question to a community of 473,224 software developers and data experts.

Calculating Date Differences Help Needed

What's a good way to calculate the number of days between two dates in
the following format:

2003-07-15
2003-08-02

I've looked at the PHP date functions but I'm still a bit lost...

Jul 16 '05 #1
6 9022
Yeah, I follow that - but I end up with a unix epoch date - how can I
determine how many days diff that represents? In other words, per
your suggestion I can get date1 and date2 and determine via mktime the
diff - but I still need to know how many days diff that is???

On Sun, 03 Aug 2003 03:18:26 GMT, Blaine HIlton
<bl***************@verizon.net> wrote:
What you need to do is check the mktime() function at
http://www.php.net/manual/en/function.mktime.php.

Basiclly you would use mktime and send the function the date and call
that date1 and then another mktime and call that date2. Then just
subtract. mktime() will give you the unix epoch date.
Also for a good example check out
http://www.befriend.com/code_gallery..._elapsed_time/, however
there are I believe 2 errors where a division sign should be a
multiplication.

Mine looks like:

//$divider['months'] = ( 60 * 60 * 24 * 365 / 12 );
$divider['months'] = ( 60 * 60 * 24 * 365 * 12 ); // cheanged
this one too
// $divider['weeks'] = ( 60 * 60 * 24 / 7 );
$divider['weeks'] = ( 60 * 60 * 24 * 7 ); // I changed / to *

and can be seen in action at http://www.webcalc.net/calc/0529.php.


Jul 16 '05 #2
I would say first check out the 3 links that I gave:

http://www.php.net/manual/en/function.mktime.php
http://www.befriend.com/code_gallery..._elapsed_time/
http://www.webcalc.net/calc/0529.php

If you read through there you will have it working. Once you have the
time from epoch for each date you subtract. That gives you the
seconds, then times by 60 for minutes, then 60 more for hours then 24
for days.

--
Blaine Hilton
http://www.webcalc.net/
On Sun, 03 Aug 2003 06:00:32 GMT, Ralph Freshour <ra***@primemail.com>
wrote:
Yeah, I follow that - but I end up with a unix epoch date - how can I
determine how many days diff that represents? In other words, per
your suggestion I can get date1 and date2 and determine via mktime the
diff - but I still need to know how many days diff that is???

On Sun, 03 Aug 2003 03:18:26 GMT, Blaine HIlton
<bl***************@verizon.net> wrote:
What you need to do is check the mktime() function at
http://www.php.net/manual/en/function.mktime.php.

Basiclly you would use mktime and send the function the date and call
that date1 and then another mktime and call that date2. Then just
subtract. mktime() will give you the unix epoch date.
Also for a good example check out
http://www.befriend.com/code_gallery..._elapsed_time/, however
there are I believe 2 errors where a division sign should be a
multiplication.

Mine looks like:

//$divider['months'] = ( 60 * 60 * 24 * 365 / 12 );
$divider['months'] = ( 60 * 60 * 24 * 365 * 12 ); // cheanged
this one too
// $divider['weeks'] = ( 60 * 60 * 24 / 7 );
$divider['weeks'] = ( 60 * 60 * 24 * 7 ); // I changed / to *

and can be seen in action at http://www.webcalc.net/calc/0529.php.


Jul 16 '05 #3
I did check out the links you gave me - I understand the epoch number
now - but when I do the math to get the number of days difference I
get a huge number:

// get todays date
$now = time();
print "<br>now: $now";
$then = mktime(0,0,0,8,15,2003);
print "<br>then: $then";
$diff = $now - $then;
print "<br>diff: $diff";
$min = $diff * 60;
print "<br>min: $min";
$hours = $min * 60;
print "<br>hours: $hours";
$days = $hours * 24;
print "<br>days: $days";

$days is a huge number and there is not that many days diff between
time() and august 15, 2003 - what am I not understanding here?
On Sun, 03 Aug 2003 07:23:52 GMT, Blaine HIlton
<bl***************@verizon.net> wrote:
I would say first check out the 3 links that I gave:

http://www.php.net/manual/en/function.mktime.php
http://www.befriend.com/code_gallery..._elapsed_time/
http://www.webcalc.net/calc/0529.php

If you read through there you will have it working. Once you have the
time from epoch for each date you subtract. That gives you the
seconds, then times by 60 for minutes, then 60 more for hours then 24
for days.


Jul 16 '05 #4
Ralph Freshour wrote:
I did check out the links you gave me - I understand the epoch number
now - but when I do the math to get the number of days difference I
get a huge number:

// get todays date
$now = time();
print "<br>now: $now";
$then = mktime(0,0,0,8,15,2003);
print "<br>then: $then";
$diff = $now - $then;
print "<br>diff: $diff";
$min = $diff * 60;
print "<br>min: $min";
$hours = $min * 60;
print "<br>hours: $hours";
$days = $hours * 24;
print "<br>days: $days";

$days is a huge number and there is not that many days diff between
time() and august 15, 2003 - what am I not understanding here?

What you're not understanding is the fact that his math was wrong ;) If
you've got 60 seconds in a minute, then there are 60 / 60 = 1 minute in
a minute, not 60 * 60 = 3600 minutes in a minute. Change all those * to
/ and it should work.

Jul 16 '05 #5
I got it - I finally got it to work...

Thanks...

On Sun, 03 Aug 2003 07:23:52 GMT, Blaine HIlton
<bl***************@verizon.net> wrote:
I would say first check out the 3 links that I gave:

http://www.php.net/manual/en/function.mktime.php
http://www.befriend.com/code_gallery..._elapsed_time/
http://www.webcalc.net/calc/0529.php

If you read through there you will have it working. Once you have the
time from epoch for each date you subtract. That gives you the
seconds, then times by 60 for minutes, then 60 more for hours then 24
for days.


Jul 16 '05 #6
Yes sorry about that / is a big difference then ;-)

--
Blaine

On Sun, 03 Aug 2003 10:35:48 -0400, Joshua Ghiloni
<jd***@SPAM.ME.AND.DIE.cwru.edu> wrote:
Ralph Freshour wrote:
I did check out the links you gave me - I understand the epoch number
now - but when I do the math to get the number of days difference I
get a huge number:

// get todays date
$now = time();
print "<br>now: $now";
$then = mktime(0,0,0,8,15,2003);
print "<br>then: $then";
$diff = $now - $then;
print "<br>diff: $diff";
$min = $diff * 60;
print "<br>min: $min";
$hours = $min * 60;
print "<br>hours: $hours";
$days = $hours * 24;
print "<br>days: $days";

$days is a huge number and there is not that many days diff between
time() and august 15, 2003 - what am I not understanding here?

What you're not understanding is the fact that his math was wrong ;) If
you've got 60 seconds in a minute, then there are 60 / 60 = 1 minute in
a minute, not 60 * 60 = 3600 minutes in a minute. Change all those * to
/ and it should work.


Jul 16 '05 #7

This thread has been closed and replies have been disabled. Please start a new discussion.

Similar topics

5
by: Ron Adam | last post by:
Hi, I'm having fun learning Python and want to say thanks to everyone here for a great programming language. Below is my first Python program (not my first program) and I'd apreciate any...
10
by: riki | last post by:
hello, i need to calculate num of days between 2 dates... i get separate parts of dates from html form, then i need to "make" begining and ending date and calculate difference between them......
12
by: Anthony Robinson | last post by:
Is anyone aware of a function (system or user defined) that will calculate business days? For instance: I have a column in as table called DATE. I want to be able to add five business days to that...
1
by: Tony Williams | last post by:
I have a table with two fields, txtvalue (a number field) and txtmonth ( a date/time field). I want to create a report that shows the difference in value between the value in txtvalue in one value...
1
by: pauly | last post by:
Hello All, I have been trying to create a query that extracts data from a table and calculates the elapsed time between records. The table called "Imported_table". I need to be able to calculate...
1
by: b.beeching | last post by:
Not sure if my subject is entirely accurate but here goes. I need to calculate the date difference between a date A and a date B... however date B relies entily on date A. EG: i have an advert...
6
by: krishnakant Mane | last post by:
hello, I am strangely confused with a date calculation problem. the point is that I want to calculate difference in two dates in days. there are two aspects to this problem. firstly, I can't get...
1
by: rodneyeid | last post by:
Hi, I have an attendance machine which saves records in an Access Database in the following format : UserID DATE/TIME Checktype where if checktype is 0 then its check in and if it is 1 then it...
5
by: cbalian | last post by:
I am looking for a TSQL code that would calculate a specific date each month that varies based on the following condition: I need the result that would return the date of the Thursday after the...
0
by: VivesProcSPL | last post by:
Obviously, one of the original purposes of SQL is to make data query processing easy. The language uses many English-like terms and syntax in an effort to make it easy to learn, particularly for...
3
isladogs
by: isladogs | last post by:
The next Access Europe meeting will be on Wednesday 3 Jan 2024 starting at 18:00 UK time (6PM UTC) and finishing at about 19:15 (7.15PM). For other local times, please check World Time Buddy In...
0
by: jianzs | last post by:
Introduction Cloud-native applications are conventionally identified as those designed and nurtured on cloud infrastructure. Such applications, rooted in cloud technologies, skillfully benefit from...
0
by: mar23 | last post by:
Here's the situation. I have a form called frmDiceInventory with subform called subfrmDice. The subform's control source is linked to a query called qryDiceInventory. I've been trying to pick up the...
2
isladogs
by: isladogs | last post by:
The next Access Europe meeting will be on Wednesday 7 Feb 2024 starting at 18:00 UK time (6PM UTC) and finishing at about 19:30 (7.30PM). In this month's session, the creator of the excellent VBE...
0
by: fareedcanada | last post by:
Hello I am trying to split number on their count. suppose i have 121314151617 (12cnt) then number should be split like 12,13,14,15,16,17 and if 11314151617 (11cnt) then should be split like...
0
by: stefan129 | last post by:
Hey forum members, I'm exploring options for SSL certificates for multiple domains. Has anyone had experience with multi-domain SSL certificates? Any recommendations on reliable providers or specific...
0
Git
by: egorbl4 | last post by:
Скачал я git, хотел начать настройку, а там вылезло вот это Что это? Что мне с этим делать? ...
0
by: MeoLessi9 | last post by:
I have VirtualBox installed on Windows 11 and now I would like to install Kali on a virtual machine. However, on the official website, I see two options: "Installer images" and "Virtual machines"....

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.