How to import a spreadsheet of events into Google Calendar

Google Calendar accepts two file types on its Import & export page: CSV and ICS. Both are desktop-web only; the mobile apps have no import option, and sync carries imported events to your phone.

The CSV importer is strict. It expects Google's own header names (Subject, Start Date, Start Time, End Date, End Time, All Day Event, Description, Location, Private), dates in US month/day/year order, and times such as 9:00 AM. There is no preview: a bad header or a misordered date shows up after the events are already in your calendar.

The .ics route means converting the spreadsheet to an iCalendar file first. Columns are matched to calendar fields before Google sees anything, dates are resolved in whatever order your sheet uses, each event carries its own exact time, and you can inspect the result before you commit.

Use Google's CSV import when the file already matches its layout, in practice an export from Outlook or from Google Calendar itself. Use .ics for anything else: your own sheet, a school or booking-system export, day-first dates, or more than one time zone.

Either route needs one event per row and the column names in row 1, with nothing above them; a banner row stops the real headers from being recognized.

A cell that says 09:00 says nothing about where 09:00 is. Google's CSV import assumes the time zone of the calendar you import into. If that calendar is on Pacific Time and the schedule was written for Berlin, every session lands nine hours early, and nothing warns you.

An .ics file can carry absolute instants instead. Koyomi asks which zone the times were written in (defaulting to your browser's) and writes each event as a UTC timestamp using the offset in force on that date, so a schedule straddling a daylight-saving change comes out right on both sides. Google displays each event in the viewer's calendar zone: 09:00 in Berlin, 00:00 in Los Angeles, which is correct.

The exception is a schedule meant to read the same everywhere, such as a bell timetable. Koyomi's "No timezone" option writes wall-clock times with no zone, and Google places those in the destination calendar's zone, as it would a CSV. A cell that already carries an offset, such as 2026-09-14T09:00:00+02:00, is taken as the instant it states and ignores the zone control.

Import into a calendar created for the purpose, never your primary one. There is no undo and no way to select everything that came from one file. The fix for a bad import is to delete the whole calendar from its settings, create it again, and import the corrected file. Your primary calendar can't be deleted, only emptied, and emptying it takes your own events with it.

A dedicated calendar also gets its own color, one checkbox to hide the set, and can be shared once instead of emailing the file around.

Re-importing the same file into the same calendar doesn't double the events, provided each event's UID is unchanged; Google matches on UID and updates the existing event. Koyomi derives the automatic UID from the row's position, title and start, so a second conversion of the same sheet lines up with the first import. Move a row, retitle it or change its start and it arrives as a new event beside the old one. An ID column with a unique value per row is used as the UID when present and survives such edits.

A spreadsheet row is one event. Google's CSV layout has no recurrence field and Koyomi writes no recurrence rules, so neither route can say "every Tuesday until December". A spreadsheet expresses the list of occurrences instead, which for most real schedules is the better representation.

For a weekly class, type the first date, type the next one a week later, select both cells and drag the fill handle to the end of term. Each row becomes its own event, so a canceled week is a deleted row and a moved session is an edited date. You lose Google's "this and following events" edit; for a genuinely regular series with no exceptions, creating one recurring event by hand is quicker than any import.

Google Sheets has no export to Google Calendar. The add-ons and scripts that bridge the gap need write access to your calendar; downloading a file needs nothing.

File, Download, Comma Separated Values (.csv) writes the current tab only, using each cell's display text. A column formatted as "Sep 14" exports without a year and can't be placed: apply a full date format first (Format, Number, Date), or download as Microsoft Excel (.xlsx), which keeps date cells as real dates and includes every tab.

The spreadsheet locale under File, Settings decides whether a CSV comes out as 9/14/2026 or 14/09/2026. Either is fine; consistency within the column is what counts.