DateTime::add adds hours even when interval should only be seconds

Question

This comes from my previous question on getting the average time interval over a specified data set, [located here][1]. I\'ll post the entire function again:

fun         


        

Answer 1

Hm, average difference in seconds, why that PHP swath of code if your database can give it to you:

SELECT 
  SEC_TO_TIME(MAX(TIME_TO_SEC(TIMEDIFF(end_time,start_time)))) AS max_timediff,
  SEC_TO_TIME(MIN(TIME_TO_SEC(TIMEDIFF(end_time,start_time)))) AS min_timediff,
  SEC_TO_TIME(AVG(TIME_TO_SEC(TIMEDIFF(end_time,start_time)))) AS avg_timediff,
  SEC_TO_TIME(SUM(TIME_TO_SEC(TIMEDIFF(end_time,start_time)))) AS sum_timediff,
  COUNT(id) as total_events
FROM atb_log 
WHERE 
  siteID=:siteID 
  AND start_time > :fromDate
  AND end_time < :toDate

Format those min/max/avg/sum of seconds as you like.

Answer 2

As I wrote in the answer to your other question, this is a DST (Daylight Savings Time) problem. In the U.S., DST has already begun; in Europe not.

Try this code:

timecheck("Europe/Amsterdam");
timecheck("America/Los_Angeles");

function timecheck($timezone) {
date_default_timezone_set($timezone);

$totalATB=new DateTime("@0");
$t1 = "2014-01-01 17:30:00";
$t2 = "2014-01-01 17:35:00";

$dt1 = new DateTime($t1);
$dt2 = new DateTime($t2);

$timeDiff = date_diff($dt1, $dt2, true);

printf("[%s] Starting with with: %s\n", $timezone, $totalATB->format("H:i:s"));
$totalATB->add($timeDiff);
printf("[%s] added %s, total is now: %s\n", $timezone, $timeDiff->format("%H:%I:%S"), $totalATB->format("H:i:s"));
}

The output:

[Europe/Amsterdam] Starting with with: 00:00:00
[Europe/Amsterdam] added 00:05:00, total is now: 00:05:00
[America/Los_Angeles] Starting with with: 00:00:00
[America/Los_Angeles] added 00:05:00, total is now: 01:05:00