PHP if date is older than X days - php

Question

I have some problems with dates. I need make if like --->
if your activity is less than 1 day do somethink
else if your activity is more than 1 day and less than 3 do moething else
else if your activity is more than 3 do moething else
I need this in PHP. My actual code is:
if (strtotime(strtotime($last_log)) < strtotime('-1 day') ) {
$prom .= "" . json_encode('last_activity') . ": " . json_encode("inactive less than 1 day") . ",";
} else if (strtotime($last_log) > strtotime('-1 day') && strtotime($last_log) < strtotime('-3 day')) {
$prom .= "" . json_encode('last_activity') . ": " . json_encode("inactive more than 1 day and less than 3 days") . ",";
} else if (strtotime($last_log) > strtotime('-3 day')) {
$prom .= "" . json_encode('last_activity') . ": " . json_encode("inactive more than 3") . ",";
}
I think I really don't understand date calculations.

Answer 1

Date_diff is much easier in this case:
$datetime1 = date_create(); // now
$datetime2 = date_create($last_log);
$interval = date_diff($datetime1, $datetime2);
$days = $interval->format('%d'); // the time between your last login and now in days
see: http://php.net/manual/en/function.date-diff.php
Or in your way:
if(strtotime($last_log) < strtotime('-1 day')){
// it's been longer than one day
}

Answer 2

If you want to do it with strtotime, do it like this:
date_default_timezone_set('SOMETHING FOR YOU');
$last_log = '-0.5 day';
$last_log_time = strtotime($last_log);
$minus1day_time = strtotime('-1 day');
$minus3day_time = strtotime('-3 day');
echo $last_log_time . "<br>";
echo $minus1day_time . "<br>";
echo $minus3day_time . "<br>";
if ($last_log_time < $minus3day_time)
{
echo "inactive more than 3";
}
elseif ( ($last_log_time <= $minus1day_time) && ($last_log_time >= $minus3day_time) )
{
echo "inactive more than 1 day and less than 3 days";
}
elseif ($last_log_time > $minus1day_time)
{
echo "inactive less than 1";
}
Couple things I changed from your code:
remove the strtotime(strtotime()). Do not do it twice!
For your second if, I added parentheses to ensure correct evaluation of conditions.
I reversed the order of your if. First check if it is very old (so < -3). Then check if it is between -3 and -1. Then check between -1 and now.
Added <= and >=. The = cases were missing from your code. So if the last_log was == -1, it was not processed ever.
I replace "else if" by "elseif".
I used variables because recalculating strtotime all over is wasteful. And it makes the code less readable IMHO.
Then apply the json_encode comment.
To explain why the logic was reversed:
the last login of a user will always be before now.
lets say that the user's last_login is 5 days ago. strtotime($last_login) will be smaller than strtotime('-1 days'), so the if will be true. But that is not what the OP wants! He wants here the case where the last login is older than 3 days.
Remember that we are comparing numbers in the past, so the smaller, the older.

Answer 3

$dateLog = new DateTime($last_log); // format if needed
$tomorrow = new DateTime("tomorrow");
$yesterday = new DateTime("yesterday");
$threeDaysAgo = new DateTime("-3 days");
if ($dateLog < $yesterday) {
// Do what you want
} else if ($dateLog > $yesterday && $dateLog < $threeDaysAgo) {
// Do another thing
} else if ($dateLog > $threeDaysAgo) {
// ...
}
The doc is here : http://php.net/manual/en/datetime.diff.php