以正确的格式比较日期

Question

I am having all sorts of issues trying to find matching formats to compare against and I can't understand how it can be so hard to compare 2 x dates and I guess it's just above me.

I have a date in a MySQL database: 20/12/17

The report date is: 19/01/18 (it will eventually be todays date but I am testing on an old file)

I just want to find dates in 0-30 days, 31-60 days, 61-90 days and 91+ days

I convert the dates to timestamp so I can do a comparison > or < but I'm having trouble moving the date to 30 days.

I tried converting to a DateTime and using date_sub but it seems to convoluted...

All I want to do is check to see if the date string in the db is within one of the date ranges but i'm struggling.

I try using strtotime with '-30 days' I tried DateTime with date_sub

I think I am just really confused now and can't figure anything out

Here is what I have:

        $RO_Date = date_format( date_create_from_format( 'd/m/y',  $RO["RO Date"] ), 'Y-m-d' );
        $todaysDate = date_format(date_create_from_format('d/m/y', '19/01/18'), 'Y-m-d' );// Using date file was sent

        echo $RO_Date;
        echo ' ('.strtotime( $RO_Date).') ';
        echo ' <br> ';
        echo $todaysDate;
        echo ' (' . strtotime($todaysDate) . ') ';
        echo ' <br> ';
        echo ' -30 Days ';
        echo ' (' . date("Y-m-d", strtotime("-30 days", $todaysDate)) . ') ';

        if (strtotime($RO_Date) >= $todaysDate-30 ) :
            echo ':CURRENT<br>';
        elseif (strtotime($RO_Date) >= $todaysDate-60 ) :
            echo ':31-60<br>';
        elseif (strtotime($RO_Date) >= $todaysDate - 90 ) :
            echo ':61-90<br>';
        elseif (strtotime($RO_Date) >= $todaysDate - 120 ) : 
            echo ':90-120<br>';
        else :
            echo ':120+<br>';
        endif;

Output:

2017-12-20 (1513688400) 
2018-01-19 (1516280400) 
-30 Days (1969-12-02) :CURRENT
2018-01-03 (1514898000) 
2018-01-19 (1516280400) 
-30 Days (1969-12-02) :CURRENT
2018-01-05 (1515070800) 
2018-01-19 (1516280400) 
-30 Days (1969-12-02) :CURRENT
2018-01-12 (1515675600) 
2018-01-19 (1516280400) 
-30 Days (1969-12-02) :CURRENT
2018-01-18 (1516194000) 
2018-01-19 (1516280400) 
-30 Days (1969-12-02) :CURRENT
2018-01-18 (1516194000) 
2018-01-19 (1516280400) 
-30 Days (1969-12-02) :CURRENT

Answer 1

<?php
    $todaysDate = date_format(date_create_from_format('d/m/y', '19/01/18'), 'Y-m-d' );// Using date 
    $todaysDate = strtotime($todaysDate);
    echo $todaysDate . PHP_EOL;
    $todaysDate = date("Y-m-d", strtotime("-30 days", $todaysDate));
    echo $todaysDate;

Output:

1516316400

2017-12-20

In this line

$todaysDate = date("Y-m-d", strtotime("-30 days", $todaysDate));

$todaysDate needs to be a timestamp not a date string, that was the mistake

See http://php.net/strtotime

Answer 2

<?php
    function dateDiff($dateStringFromDB){
    $today     = new DateTime("Now");
    $db_string = new DateTime($dateStringFromDB);
    $days      = $today->diff($db_string)->format('%d'); 

    return $days;
    }
?>

The function above calculates the difference between the current date and any date passed to the function and returns the number of days. Example: if $dateStringFromDB is 17/04/2018 and $today is 15/04/2018, it returns the value of $days as 2.

use:

echo dateDiff($dateStringFromDB);

You can now use the result for whatever you want.