I have two dates in the format YYYY-MM-DD and I want to compare them do do some task.

I tried this piece of code:

```
         $temp_date = strtotime($cu['date']);
         $temp_upto = strtotime($upto_date);

         if($temp_date <= $temp_upto){
            echo "<tr id='highlight'>"; 
        }else{
            echo "<tr>";
            }

```

`$cu` is an array and contains date in the same format. Is this the correct way to compare dates in php?
The output which I get is quite weird! I haven't posted the full code because its too long and irrelevant for this question.
Thanks!.

**UPDATE:** So this is what I am trying to do. I have many normal dates and I have a upto date if the normal dates are less than or equal to upto date then I want the id="highlight" added to . THe whole thing is inside a loop for some other purpose of my code.

I echoed the dates like this:

```
 echo "DATE: " . $temp_date + " UPTO: " . $upto_date;

```

and the output was something like

```
DATE: 1349042400 UPTO: 00-00-0000
DATE: 1349388000 UPTO: 00-00-0000
DATE: 1352588400 UPTO: 00-00-0000
DATE: 1352761200 UPTO: 00-00-0000
DATE: 1353193200 UPTO: 00-00-0000
DATE: 1353366000 UPTO: 1353193200
DATE: 1354143600 UPTO: 1353193200
DATE: 1354662000 UPTO: 1353193200

```

still the comparison doesn't happen. and I dont see any change!

People who are suggestion already answered questions, I have already read and implemented most of them without any success.

**UPDATE 2:** While I am still trying to figure out my issue. I want to share the expanded code snippet here <http://pastebin.com/nsVGV9dg>