Date/Time if/else statements

[jonathen]

Hi all,

I am trying to a write statement that I can use to expire dates within my db. I want it to work, that if the two fields from the db, $expdate & $exptime are less than the current date & time ($nowdate & $nowtime), then it changes a status field in the db to EXPIRED, else, leave it as it is (ACTIVE)

I understand most of it, but to just get it to print ACTIVE or EXPIRED for my tests, I have run into problems.

To do my tests, I have used the following script:

$nowdate=date("D M j, Y");
$nowtime=date("H:i");
$expdate="Wed July 9, 2003";
$exptime="15:55";

if ($exptime <$nowtime)
{
	echo " Time is EXPIRED";
}
else
{
	echo "Time is ACTIVE";
}
echo "<br>";
if ($expdate <$nowdate)
{
	echo " Date is EXPIRED";
}
else
{
	echo "Date is ACTIVE";
}

That works fine - this statement, with my variables prints:
Time is EXPIRED
Date is ACTIVE

Perfect. But here's the thing I cannot do. I want to join them together so that if $expdate AND $exptime are less than $nowdate AND $nowtime, the result is echoed as EXPIRED, else the result is ACTIVE.

How do I do this? Any help appreciated.

Jonathen

[pete_bisby]

Put your if statements together with an AND (&&):

if (($exptime<$nowtime) && ($expdate<$nowdate)) {
   echo "Date/Time is EXPIRED";
} else {
   echo "Date/Time is ACTIVE";
}

[jonathen]

Thanks for that, that is what I am after. However, it doesn't seem to work properly...

I use the following:

$nowdate=date("D M j, Y");
$nowtime=date("H:i");

$expdate="Tue July 8, 2003";
$exptime="15:55";

if (($expdate<$nowdate) && ($exptime<$nowtime)) { 
   echo "Date/Time is EXPIRED"; 
} else { 
   echo "Date/Time is ACTIVE"; 
}
echo "<br><br>";
echo "Exp: $expdate - $exptime";
echo "<br>";
echo "Now: $nowdate - $nowtime";

...which prints this:

Date/Time is ACTIVE

Exp: Tue July 8, 2003 - 15:55
Now: Tue Jul 8, 2003 - 17:50

The Date/Time should be expired! Makes no difference is I use < or >

Am I missing something? Thanks in advance.

[pete_bisby]

It might be better if you convert your dates to a numerical string, or even a number.
It could be getting confused with your values, and comparing them as a string and not as a date.
For example, Tuesday is before Thursday in the week, but alphabetically its the other way round.

Have a look at the date() and mktime() functions to create your strings, then compare them as before - it should work.

[128kb_com]

pete_bisby is on the right track except instead of coverting your date to a string you simply need to covert your date to the number of seconds from time of Epoch (unix timestamp). Once all your times are in seconds, then you'll be able to compare them with a simple boolean < or > expression. see mktime()

[jonathen]

Ah, of course - that would make sense. Thanks guys for all your help 🙂

Jonathen

[jonathen]

Okay, this doesn't make sense. I converted my dates to mm:dd:yyyy and ran the compare, and still it retyrns ACTIVE if the dates are the same but the times are different.

I know it has something to do with combining date & time, because if I run:

$nowtime=date("H:i");
$exptime="15:55";

if ($exptime<$nowtime) { 
   echo "Time is EXPIRED"; 
} else { 
   echo "Time is ACTIVE"; 
}

...this prints "Date/Time is EXPIRED".
Good. The same happens if I do the dates on their own. But if I run:

$nowdate=date("m:d:Y");
$nowtime=date("H:i");

$expdate="07:08:2003";
$exptime="15:55";

if (($expdate<$nowdate) && ($exptime<$nowtime)) { 
   echo "Date/Time is EXPIRED"; 
} else { 
   echo "Date/Time is ACTIVE"; 
}

It returns "Date/Time is ACTIVE". But it should be expired!

What am I missing? This is madness.

Any help greatly appreciated.

[YappyDog]

The problem with your script is that you are checking if the date is less than something (today) and the time is less than now. If the dates are equal, your if statement fails. To fix the if statement, you just need to check for less than or equal to (<=).

BUT, as someone said earlier, you'd be better off not comparing strings and just comparing the unix timestamps.

[Weedpacket]

Another problem is that sorting that way would put April 2006 before August 2002. (e.g., "04:12:2006" < "08:12:2002").

Either use a Unix timestamp as suggested, or a date format like "YYYY-mm-dd hh:mm:ss". Dates/times written in that format sort the same way both as strings and chronologically, which is why it's the ISO standard.

[jonathen]

Thanks guys, that explains alot 🙂

[128kb_com]

Read my last post more carefully. You can convert almost any datestamp with almost any format (e.i. MM:YY😃D) into seconds (from time of Epoch (January 1 1970 00:00:00 GMT)). So this way your datestamps are a single whole number which can be compared to another single whole number.

Format your date into separate variables, then convert to GMT:

/* gmmktime() and mktime() are both good canidates for the job */
$gmt1 = gmmktime($h, $min, $sec, $mon, $d, $y);
$gmt2 = gmmktime($h2, $min2, $sec2, $mon2, $d2, $y2);

/* now $gmt1 and $gmt2 are whole numbers, time in seconds */

if ($gmt1 > $gmt2) {
    // do something ...
}
// ....

Have a look at the
Date/Time functions

[jonathen]

Hi,

I decided not to convert to whole numbers, as the code I was using with the yyyy:mm:dd && hh:mm was comparing correctly within my test. So I thought, great, I'll try it in the purpose I want it for - to update the "status" field within my db to expired or active.

The following code marks ALL rows "expired", unless I change the >= to a <= in which case it marks all "active". The thing is, I have tested this, and have 2 entries with past times (should expire) and two with future times (should stay active) - one future time is a few hours in the future and one is a few days in the future. Yet why are all being marked expired or all active? I am sure it's not the compare that is broken, I think it has something to do with the additional code within my function - is there anything wrong with the below? Sorry to be so dense, but I have never worked with dates/times or comparing them, so this is not the easiest thing for me 🙂

function CalculateDateDiff() {
require "../mysql.info.php";
$nowdate=date("Y:m:d");
$nowtime=date("H:i");

$link = mysql_connect("$sqlhost","$sqllogin","$sqlpass") or die(mysql_error());
mysql_select_db("$sqldb",$link) or die(mysql_error());
$query="SELECT expdate,exptime FROM standby" or die(mysql_error());
$result=mysql_query($query) or die(mysql_error());
mysql_close(); 
$expdate=mysql_result($result,$i,"expdate");
$exptime=mysql_result($result,$i,"exptime");

if (($expdate>=$nowdate) && ($exptime>=$nowtime)) { 
$link = mysql_connect("$sqlhost","$sqllogin","$sqlpass") or die(mysql_error());
mysql_select_db("$sqldb",$link) or die(mysql_error());
$query="UPDATE standby SET status='EXPIRED'" or die(mysql_error());
mysql_query($query) or die(mysql_error());
mysql_close(); 
} else {
$link = mysql_connect("$sqlhost","$sqllogin","$sqlpass") or die(mysql_error());
mysql_select_db("$sqldb",$link) or die(mysql_error());
$query="UPDATE standby SET status='ACTIVE'" or die(mysql_error());
mysql_query($query) or die(mysql_error());
mysql_close(); 
}
}

Thanks,

Jonathen

[jonathen]

Doh! Ignore my last message - I was being stupid. Forgot to loop the query.