Daylight saving time (DST) moves clocks forward an hour in spring and back an hour in fall. On those days, a day is 23 or 25 hours long. The exact dates differ by country and region, so check when the change happens where your team works.

This article explains how Assembled handles those days and what to check beforehand.

How Assembled handles daylight savings time

Shifts and events on your team's schedule, time off, forecasts, and data from your integrations are saved as exact moments in time. So a time time change doesn't impact the data itself; it only changes how they're displayed relative to the exact moment they're scheduled to start. 

However, some areas of the Assembled app like templates, working hours, and recurring events save time stamps with a time zone reference (i.e. 9:00 AM in America/Chicago). Assembled works out the real times separately for each day using that day's rules, so a 9 AM start stays at 9 AM local time before and after a change. The time zone that's used depends on the area of Assembled you're viewing.

• Templates use their own time zone, which you choose when you create the template.
• Working hours use the time zone set on each rule.
• Recurring events use the time zone chosen when the event is created.
• Your schedule views show your own time zone from My settings. You can add more time zones to the staffing timeline.

The staffing timeline on change days

In day view, an icon marks the first hour after the change. Hover over it to see "Daylight saving time begins" or "Daylight saving time ends." In week view, that day's column is slightly narrower or wider than the others.

Working hours and schedule generation, templates, and recurring events on change days

• Start times stay consistent. An event that starts at 9 AM on other days starts at 9 AM on a change day.
• Each event keeps its length. Events that run through the change end an hour later on the clock in spring, or an hour earlier in fall.
  • Example: a 2-hour event from 1:00 AM to 3:00 AM runs from 1:00 AM to 4:00 AM on spring-forward day.
  • On fall-back day it runs from 1:00 AM to 2:00 AM. That's still 2 hours, because 1 AM happens twice.
• Overnight shifts work the same way. A working hours shift from 10 PM to 6 AM ends at 7 AM after spring forward and at 5 AM after fall back. It's still 8 hours long.
• Starts in the skipped or repeated hour move. An event set to start during the skipped hour (for example, 2:30 AM in the US) moves by one hour. An event set to start during the repeated hour is placed in one of its two occurrences.

Tip: if you schedule anything between 1 AM and 3 AM, check the change day after you apply a template.

Forecasts on change days

When Assembled builds a forecast, it lines up past data by local time, using the time zone of the queue's business hours (or your company's default time zone). That way a Monday at 9 AM is compared with past Mondays at 9 AM, even across a change.

Uploading forecasts

Times in a forecast CSV are read in the time zone you choose on the upload form. A file in local time can't describe a change day cleanly - since a skipped hour doesn't exist, so rows for it can't be saved as written, and a repeated hour appears twice causing both rows land in the same interval. If you can, export your forecast in UTC and choose UTC on the upload form. 

Reports on change days

• Hourly and 15-minute reports show 23 or 25 hours for a change day.
• Daily and longer totals use your company's default time zone, so a change day is a single 23- or 25-hour day.
• Some reports show a warning when your date range includes a time change, such as Trends and Forecasted vs Actual. Daily totals or averages for some metrics on and after that date may be off. To get accurate daily totals, select a range that doesn't include the change day, and look at the change day separately.

Preparing for a time change

You can do all of this before the change date.

1. Open the staffing timeline on the change date and check your coverage.
2. Look for shifts and events between 1 AM and 3 AM, and for overnight shifts that run through the change.
3. If you've applied a template to the change week, check that day after applying.
4. Upload forecasts for the change week in UTC.
5. For reports, select date ranges that start or end around the change day.
6. Make sure each person's time zone is set to the city where they work (for example, America/Chicago), not a fixed offset.

7. Keep your browser and operating system up to date. Some views use your browser's built-in time zone information.

    

Note: When a region stops observing daylight saving time

Governments sometimes end or change daylight saving time. For example, starting November 1, 2026, British Columbia, Alberta, Manitoba, the Northwest Territories, and northwestern Ontario stop changing their clocks. They stay on their current summer time all year.

How Assembled handles it

Assembled uses the public time zone database, which records the rules for each region under a city-based time zone name, such as America/Vancouver. When a region changes its rules, the database is updated, and we update Assembled with it ahead of the change. After that:

• Templates, working hours, and recurring events set to the region's time zone follow the new rules automatically. A 9 AM start stays at 9 AM local time.
• The staffing timeline, My schedule, and reports show the new offset. There's no 25-hour day for the region on the old fall-back date.
• Differences between time zones change. For example, in winter Vancouver will be 2 hours behind New York instead of 3. If you schedule agents in these regions from a template in another time zone (such as Eastern time), their local start times will be an hour different in winter. Review those schedules.
• Shifts already on the schedule are exact moments, so they don't move. If a template was applied to dates after the change before Assembled was updated, re-apply it for those dates.
• Forecasts don't need any changes, because past data is lined up by local time.

What you should do

• Set each person to the city-based time zone for where they work (for example, specifically use America/Vancouver instead of America/Los Angeles). Don't use a fixed offset or a nearby time zone.
• Keep your browser and operating system up to date. Some views use your browser's built-in time zone information.