Wrong event times from Google Sheets™ to Calendar™

When a 09:00 event appears at 05:00, first compare the spreadsheet’s time zone with Calendar’s display time zone. They can show the same instant on different clocks.

Check the two settings

EventFill reads dates and times in the spreadsheet’s time zone. Find it under File > Settings > Time zone. This applies to the whole spreadsheet, including its other tabs; Google explains the spreadsheet settings. All rows in an EventFill run use this zone. Convert times from other zones before entering them.

In Google Calendar, check Settings > General > Time zone > Primary time zone. Google’s Calendar time-zone guide explains that events appear in each viewer’s local zone. You can also display an additional zone beside the calendar grid. Compare the event in the intended zone before changing the time in the sheet.

Use dates and times with a clear meaning

Use real date/time cells, or unambiguous text such as 2026-10-26 and 09:00. A text date like 03/04/2026 is ambiguous; a real date cell may already have been interpreted according to the spreadsheet’s locale. Changing its display format does not fix a date entered with the wrong meaning. =DATE(2026,10,26) and =TIME(9,0,0) avoid that ambiguity in an English-locale sheet.

EventFill uses minute precision: valid time text such as 09:30:59 becomes 09:30. Text seconds must be 00–59; run Check rows before adding events.

Map Start date and Start time to the correct columns. EventFill accepts a combined date/time cell too. A date with no start time becomes all-day, rather than an appointment at midnight. For a timed midnight start, use explicit date/time text such as 2026-10-26 00:00, or a separate Start time value of 00:00. Set the cell to Format > Number > Plain text before entering combined text. A genuine spreadsheet Date cell at midnight alone is still treated as date-only, so it needs the separate Start time. See the all-day guide.

A reproducible London/New York example

Use a separate test tab with just these two events and no guests. Set the spreadsheet’s locale to United Kingdom and its time zone to London (Europe/London). Enter this in A1:D3:

Format B2:B3 as dates and C2:D3 as times. In EventFill, choose Use the current sheet, map those columns, choose a test calendar and run Check rows. After adding, view Calendar with New York (America/New_York) as its primary display zone. The expected starts are:

The UK changes clocks on 25 October 2026, while US daylight saving ends on 1 November 2026. The London/New York difference changes between these rows. Subtracting a fixed number of hours from every row would give the wrong result across that boundary.

Check before a larger run

Check rows catches invalid dates, time formats and guest-address formatting without creating events or using your free allowance. It cannot know that a valid time is in the wrong zone, or which occurrence you intended during a repeated clock-change hour. Calendar permissions and service limits are checked when adding.

EventFill sends a local clock time with the spreadsheet’s zone; Google’s event time-zone documentation describes that representation. Around a clock change, an hour can repeat or disappear. For such appointments, confirm the intended instant and inspect the result in Calendar; Check rows is not a daylight-saving ambiguity detector. An overnight event crossing the change can also have a different elapsed duration from the difference between its displayed start/end clock times.

To correct already linked events, keep their Calendar event cells with their rows and rerun to the same calendar. An unlinked row creates a new event. EventFill runs when you click; changing a spreadsheet setting alone does not send an update to Calendar.