By Marc Alexander

Australia has three main time zones, and only some states use daylight saving. A GA4 property set to the wrong one, or left on the default it was created with, shifts every daily figure and makes "yesterday" mean something different to each team.

Why the setting matters.

GA4 decides which day an event belongs to using the property's time zone. If a Perth business has its property set to Sydney, a sale at 10pm in Perth lands on the next day's report.

If a property was set up from overseas, it may be on Pacific or London time, and every day's figures start and end in the middle of the Australian day.

That affects more than daily totals. Hour-of-day reports, day-of-week patterns and campaigns scheduled for a particular time all read differently.

Daylight saving.

New South Wales, Victoria, the ACT, Tasmania and South Australia move their clocks in summer. Queensland, the Northern Territory and Western Australia don't. So for half the year, Brisbane and Sydney are an hour apart, and for the other half they're the same.

Choosing the city where most of your customers or your team are, rather than a fixed offset, means GA4 follows that city's daylight saving automatically.

Changing it.

You can change the time zone in GA4's property settings. It applies from that point on, and past data isn't restated. On the day you change it, that day can look short or long by a few hours, which is worth noting for anyone comparing periods.

Other places a time zone hides.

  • Google Ads has its own account time zone. If it differs from GA4's, daily figures in the two will never line up.
  • The BigQuery export records event_timestamp in UTC and event_date in the property's time zone. Queries that group by day from the timestamp need to convert it first, or they'll split the Australian day in two.
  • Dashboards built in Data Studio or elsewhere may use their own setting. Check that they match.
  • Your store platform and CRM each have one too. Reconciling GA4 with either starts with making sure the days match.

Multi-state and international businesses.

A property can only have one time zone. A business across several states usually picks the one where head office or most customers are, and accepts that other states' days are shifted by an hour or two.

A business that also sells overseas may be better served by separate properties or reporting in BigQuery, as covered in tracking a multi-country website in GA4.

What to check.

  1. GA4 property time zone and currency, under Admin, Property details.
  2. Google Ads account time zone.
  3. Any BigQuery queries that group by date.
  4. Dashboards and platform reports used alongside GA4.

Marc Alexander sets up and audits GA4 for Australian businesses. The GA4 mini audit checks property settings first.