如何确定日期是否比当前日期晚三个月以上

Question

I am getting a date back from a mysql query in the format YYYY-MM-DD.

I need to determine if that is more than three months in the past from the current month.

I currently have this code:

$passwordResetDate = $row['passwordReset'];
$today = date('Y-m-d');

$splitCurrentDate = explode('-',$today);
$currentMonth = $splitCurrentDate[1];

$splitResetDate = explode('-', $passwordResetDate);
$resetMonth = $splitResetDate[1];

$diferenceInMonths = $splitCurrentDate[1] - $splitResetDate[1];

if ($diferenceInMonths > 3) {
    $log->lwrite('Need to reset password');
}

The problem with this is that, if the current month is in January, for instance, giving a month value of 01, and $resetMonth is November, giving a month value of 11, then $differenceInMonths will be -10, which won't pass the if() statement.

How do I fix this to allow for months in the previous year(s)? Or is there a better way to do this entire routine?

Answer 1

Use strtotime() , like so:

$today = time(); //todays date 
$twoMonthsLater = strtotime("+3 months", $today); //3 months later

Now, you can easily compare them and determine.

Answer 2

I'd use PHP's built-in DateTime and DateInterval classes for this.

<?php

// create a DateTime representation of your start date
// where $date is date in database
$resetDate = new DateTime($date);

// create a DateIntveral representation of 3 months
$passwordExpiry = new DateInterval('3M');

// add DateInterval to DateTime
$resetDate->add($passwordExpiry);

// compare $resetDate to today’s date
$difference = $resetDate->diff(new DateTime());
if ($difference->m > 3) {
    // date is more than three months apart
}

Answer 3

I would do the date comparison in your SQL expression.

Otherwise, PHP has a host of functions that allow easy manipulation of date strings: PHP: Date/Time Functions - Manual