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ICS Event Generator

Builds a valid .ics calendar event with the correct exclusive all-day end date, a reminder, and a choice of UTC or floating time.

Generators Nothing uploaded No sign-up Free, unlimited
Generators tool
Fill in the fields and press Generate.
In short ICS Event Generator is a free online tool on inputtesthub.com that builds a valid .ics calendar event with the correct exclusive all-day end date, a reminder, and a choice of UTC or floating time. It needs no account, no download and no payment, and there is no daily usage limit. Everything is processed inside your own browser, so the data you paste is never uploaded to a server.

How to use the ICS Event Generator

  1. Enter the title and the start.
  2. Turn on all-day if there is no time, and read the note about the end date.
  3. Choose UTC for a meeting, Floating for a birthday.
  4. Download the .ics.

About the ICS Event Generator

The ICS Event Generator builds a valid .ics calendar event with the correct exclusive all-day end date, a reminder, and a choice of UTC or floating time. It runs as plain JavaScript inside the page, which means there is no upload step, no queue and no size limit imposed by a server — the only limit is your own device.

What people use it for

  • Attaching an event to an email so one click adds it.
  • Publishing a webinar date visitors can save.
  • Sending a booking confirmation that lands in the calendar.

Details

StandardRFC 5545, iCalendar 2.0
All-day DTENDExclusive — a one-day event ends on the following day
Line endingsCRLF, which Outlook requires and others tolerate
ReminderA VALARM with a negative trigger
The reminder is written as a VALARM with a negative trigger, meaning "this many minutes before the start". Support varies: Google Calendar honours it on import, and some clients quietly replace it with the user's own default. That is a client decision, not a defect in the file.

Where this tool stops

One event per file, and no attendees or invitations. A file with attendees and METHOD:REQUEST is a meeting invitation, which behaves quite differently and needs an organiser mailbox behind it.

Frequently asked questions

Why is the end date in the file a day later than I entered?
Because that is what the specification requires, and it is the mistake almost every hand-written .ics makes. An all-day <code>DTEND</code> is <b>exclusive</b> — it names the first day the event no longer covers. A single-day event on 9 August has DTSTART 9 August and DTEND 10 August. Writing the same date twice produces a zero-length event, which some calendars show a day short and others do not show at all.
What is the difference between UTC and floating time?
A UTC time is a fixed moment: 14:00 UTC is 15:00 in Berlin and 09:00 in New York, and that is right for a meeting. A floating time has no zone at all, so 09:00 stays 09:00 for everyone — right for a birthday, a public holiday, or "take the tablets at nine". Choosing UTC for something that should float is how an event drifts by a few hours for half its audience.
My .ics opens in Apple Calendar but Outlook rejects it. Why?
Almost always the line endings. RFC 5545 requires CRLF and Outlook enforces it; Apple and Google accept bare LF. Files written by a script or copied through an editor often lose the carriage returns. This tool writes CRLF.
Is the ICS Event Generator free, or is there a paid tier?
Free, unlimited, and no email address required. You can use it a hundred times a day and nothing changes.
Is the ICS Event Generator safe to use with private information?
No. The ICS Event Generator runs entirely in your browser using JavaScript. Your input never reaches inputtesthub.com or any third party — open your browser's Network tab while you use it and you will see no request go out.
Who is the ICS Event Generator for?
The jobs it is built for: attaching an event to an email so one click adds it. Publishing a webinar date visitors can save. Sending a booking confirmation that lands in the calendar. It is built for exactly those cases rather than being a general-purpose tool with this bolted on.
Where does the ICS Event Generator stop being reliable?
One event per file, and no attendees or invitations. A file with attendees and METHOD:REQUEST is a meeting invitation, which behaves quite differently and needs an organiser mailbox behind it. Knowing where a tool stops being trustworthy matters more than the cases where it works.
What are the key numbers for the ICS Event Generator?
Standard is RFC 5545, iCalendar 2.0. All-day DTEND is Exclusive — a one-day event ends on the following day. Line endings is CRLF, which Outlook requires and others tolerate. These are printed on the page itself, so you do not have to take them on trust.
Is there an app version?
Yes. The page is responsive and the utility works in Chrome, Safari, Firefox, Edge and Samsung Internet on both Android and iOS. There is no app to install and nothing to sign into.

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