Step 1 / source
Choose the source
Drop one file here
Choose a calendar export you own or are authorised to review, with complete VEVENT blocks.
Checking publication status...LOCAL CALENDAR CONVERTER / ICS TO CSV
ICS to CSV
Extract up to 1,000 VEVENT records from an ICS calendar into a formula-protected CSV without expanding recurring schedules.
Processed in this browserOne UTF-8 .ics file up to 2 MB and 1,000 VEVENT records. Each event needs DTSTART. Supported values are YYYYMMDD dates or local/UTC YYYYMMDDTHHMMSS-style times.
ICS - 1,000 events
No file upload
This operation runs with browser APIs. Nirmion receives catalogue requests, not the selected source bytes.
Original stays unchanged
The converter creates a separately named output. It never writes back into the source file.
Bounded work
One UTF-8 .ics file up to 2 MB and 1,000 VEVENT records. Each event needs DTSTART. Supported values are YYYYMMDD dates or local/UTC YYYYMMDDTHHMMSS-style times.
Plain-language method
How VEVENT properties become columns
Nirmion unfolds continued ICS lines, identifies complete VEVENT blocks, reads summary, start, end, timezone, location, description, UID, and recurrence rule properties, decodes escaped text, protects formula-like CSV cells, and writes one source event per row. It never generates recurring instances.
- 01Choose a valid source
Use a self-contained UTF-8 ICS export. DTSTART is required; DTEND, SUMMARY, TZID, LOCATION, DESCRIPTION, UID, and RRULE are optional.
- 02Review the conversion choices
ISO style makes recognised compact dates easier to read. Source style retains compact ICS date text while still placing TZID in its own column.
- 03Inspect the separate result
The output ends in _nirmion_tools_events.csv with eight stable columns. One recurring VEVENT remains one row with its RRULE text.
Useful when
Practical jobs this tool handles
- Audit an exported campaign calendar in a spreadsheet.
- Review calendar event metadata before migration.
- Create a flat event inventory without granting account access.
Before converting
Treat recurrence carefully
- Confirm the source calendar and event count.
- Review timezone values beside local date-times.
- Do not treat one recurring row as one occurrence.
Know the boundary
Recurring events are not expanded
RRULE, exclusions, overrides, alarms, attendees, and provider-specific extensions can affect a real calendar. The CSV is an event-property inventory, not a complete occurrence schedule.
Quick answers
Questions before you convert
The export stays close to source event records.
Will a weekly event create many rows?
No. One VEVENT creates one row and its RRULE remains visible as text.
Are time zones converted?
No. Local values stay local and TZID is reported separately; UTC values retain Z.
Are attendees included?
Not in this focused release. Use the original ICS when attendee and alarm detail matters.