Calculate difference between two datetimes

Question

I am using PHP and MySQL, and want to calculate date time difference between two datetimes. I have a message table, in that table createdate is one field. I want to find out day and time difference from current date in the format 1 day 2 hours ago. What is the best way to go about this?

Solution 1

Use PHP's built in date functions:

<?php
    $start_time = "Y-m-d H:i:s"; // fill this in with actual time in this format
    $end_time = "Y-m-d H:i:s"; // fill this in with actual time in this format

    // both of the above formats are the same as what MySQL stores its
    // DATETIMEs in

    $start = new DateTime($start_time);
    $interval = $start->diff(new DateTime($end_time));

    echo $interval->format("d \d\a\y\s h \h\o\u\r\s");

• DateInterval documentation
• DateTime::diff documentation

Solution 2

SELECT TIMESTAMPDIFF(HOUR,createdate,NOW()) as diff_in_hours FROM table1;

Then on php side you can easily convert the value of diff_in_hours to days + hours format.

Solution 3

You can use DATEDIFF() and TIMEDIFF() functions in MySQL.

SELECT DATEDIFF(CURDATE(), createdate) AS output_day, 
TIMEDIFF(CURDATE(), createdate) AS output_time 
FROM message_table

For output_day it is already in day unit. But output_time require additional manipulation to get the hour part of the time difference.

Hope this helps.

Comments

[Osh Mansor]

@Sanjay: The solution I wrote gives the time difference up to a fraction of a sec in the following format HH:MM:ss.s

[a1ex07]

@Sanjay: The first argument of TIMESTAMPDIFF can also be MINUTE ,or SECOND, or MICROSECOND (dev.mysql.com/doc/refman/5.5/en/…). In your question you asked about days+hours, so I put HOUR unit to my sample code.

[Vipul Hadiya]

What about <= PHP 5.2 ?