Daylight Saving Time and the Website Clock

An hour out since Sunday

The clocks went back an hour at two o'clock on Sunday morning. Most phones and computers changed by themselves.

Some websites did not, because they were never told the rules. Their clock is set to a fixed distance from Coordinated Universal Time, such as UTC-7, rather than to a place.

A fixed offset never changes, but local time does, twice a year. So a site set that way is right for half the year and an hour out for the other half.

Which half depends on when it was set up. A site given UTC-7 in July has been an hour ahead since Sunday; one given UTC-8 in winter spent the whole summer an hour behind.

Where the website clock is used

• Scheduled posts and pages that publish at a set time.
• Booking forms that offer times and close same-day slots.
• Confirmation and reminder emails sent by the site.
• Calendar attachments customers add to their phones.
• Sale prices and countdowns that start and stop automatically.
• Order times on receipts and in the shop's records.

Calendar attachments are the ones customers act on. They often store times in universal time, so a site that is an hour out sends an appointment that lands an hour out on the customer's phone.

Offset or city

In WordPress the setting is under Settings, then General, then Timezone. The list offers cities grouped by continent and, further down, plain offsets from UTC-12 to UTC+14.

Choose the city. Vancouver covers most of BC, and the site then follows the clock changes on its own.

Once a city is chosen, WordPress shows whether the zone is on standard or daylight time and when the next change falls. That line is a quick way to confirm the choice.

Drupal, Joomla and most shop platforms have a time zone setting too, and the one to choose is always a place, not a number.

Tools with clocks of their own

Fixing the site's setting is not always the end. Booking plugins, event calendars and form tools often keep a separate time zone, chosen when they were installed.

Mailing services have their own account time zone, usually picked by whoever opened the account. So do some invoicing tools.

The hosting server keeps its own clock as well. Tasks scheduled on the server, such as nightly backups or reports, run on server time, which is often Eastern or UTC.

Analytics has a time zone in each view's settings too, and it decides which day a late-evening visit or enquiry is counted on.

None of these will tell you they disagree. The only way to know is to check each one.

A worked example

A rehearsal studio in an industrial unit rents five soundproofed rooms to bands by the hour, mostly in the evenings. Bands book online, and each confirmation carries a calendar attachment.

The site launched in January, and whoever set it up chose UTC-8 from the list, which matched the clock on the wall that day.

From the middle of March, the attachments put every session an hour later than booked. A band booked from eight until ten saw nine on their phones, arrived then, and lost half their time.

Online booking also closed an hour late, at the moment each session began instead of an hour before.

On Sunday everything quietly came right again, which is what finally gave the cause away.

The setting was changed to Vancouver, the booking plugin's own time zone was corrected to match, and a check now goes in the calendar for the Monday after each clock change.

Places where the clocks stay put

Not every part of BC changes its clocks. Creston and much of the northeast, including Dawson Creek, keep the same time all year.

A business there should choose its own town from the list where one exists, such as Creston or Dawson Creek, rather than Vancouver or Edmonton.

The same goes for a business in most of Saskatchewan, which also keeps one time all year.

Checking after the change

The two days to check are the Monday after the clocks go forward in March and the Monday after they go back in November.

Make a test booking, open the confirmation email, and add its calendar attachment to a phone. The time shown should match the time you chose.

Schedule a draft post a few minutes ahead and see whether it appears on time. Look at the time on the latest order or form message too.

If anything is an hour out, the cause is almost always a fixed offset in one of the places above.

Ask whoever maintains the site to put the same two dates in their own calendar. For someone who knows where every setting lives, it is a short job.

Sales that start at a set time

Timed promotions are where an hour costs most. A Black Friday sale scheduled for midnight on a site that is an hour out starts early or late.

Countdown timers can disagree with the sale itself, because some count down on the visitor's own computer clock while the prices change on the server's.

Check the time zone before scheduling anything time-sensitive this month, rather than after customers ask why the sale has not started.

The counter-case

A site with no bookings, no scheduled posts and no automatic emails barely uses its clock. For a simple brochure site, a wrong offset is mostly invisible.

A business that books everything by phone into a paper diary has nothing on the website to drift.

Even so, the setting takes a minute to fix and affects anything added later, such as a booking form next spring. Set it to a city now, while nothing depends on it.

Setting the clock right

1. Open the time zone setting on your website.
2. Choose your city instead of a UTC offset.
3. Check the booking plugin's own time zone.
4. Check the mailing account and invoicing tools.
5. Make a test booking and open the calendar file.
6. Ask your host which time zone the server uses.
7. Add a reminder for after each clock change.

Step five is the only test that shows what customers see. Settings can look right in three places and still disagree in a fourth, and the calendar file on a phone is where that disagreement becomes a missed appointment.

The same check for the mailing account is covered in the newsletter sent at three in the morning.

Frequently asked questions

West Coast Media Solutions Inc. provides web design, web development, hosting, digital marketing, and business consulting to organisations across Canada, drawing on more than twenty-five years in the field.