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CSV to ICS Converter

シフト・授業・締切テンプレから iCalendar(.ics) を生成します。処理はブラウザ内で完結します。

必須ヘッダー: summary, start, end

Detected delimiter: ,

Security Guardrails

  • ブラウザ内処理のみ（アップロードなし）
  • CSV式文字列の中和オプション（既定ON）
  • サイズ上限: 2MB、行上限: 5000
  • バイナリ混入を検知した場合は処理を中断

CSV to ICS Converter: Guide

Intent
Convert schedule CSV files to iCalendar (.ics) with template-based validation, then import into your calendar app. Local-only processing.
What it does
Reads template-based CSV input, validates required fields/date formats/optional recurrence rules, then generates standards-friendly .ics output for calendar import.
Key features
Shift/Class/Deadline templates, Validation errors by row, Timezone mode (floating/TZID/UTC), RRULE (freq/interval/count/until/byday/bymonthday/bymonth/bysetpos/wkst), Error rows CSV export, ICS download, Local-only processing
Privacy
Everything runs locally in your browser. CSV data is not uploaded.
Best for
  • Operations teams converting existing schedule CSV files into calendar events
  • People who want to avoid manual event-by-event calendar entry
  • Users who need local-only conversion for sensitive schedule data
Why this tool
  • Template-first mapping reduces setup mistakes
  • Validation catches broken date and recurrence formats before export
  • Error rows can be exported and fixed in bulk
  • Security guardrails (formula neutralization + input limits) are built in

How to use

  1. 1Select a template (Shift, Class, or Deadline).
  2. 2Upload CSV or paste CSV text.
  3. 3Set date-time mode (floating, TZID, or UTC).
  4. 4Run Validate & Build ICS and fix any row errors.
  5. 5Download the generated .ics file and import it into your calendar.

Common mistakes

  • Using wrong date format (expected YYYY-MM-DD HH:mm or YYYY-MM-DD by template).
  • Invalid RRULE inputs (freq/interval/count/until/byday/bymonthday/bymonth/bysetpos/wkst format).
  • Missing required headers for the selected template.
  • Trying to process extremely large files beyond local safety limits.

Examples

Shift schedule import
Template: Shift Headers: summary,start,end,location,description,url Output: .ics with one VEVENT per row
Deadline import
Template: Deadline Headers: summary,due_date,description,url,all_day Output: all-day events in .ics

Related tools

CSV Inspector
Check delimiter and broken rows before conversion.
CSV Delimiter Detector
Detect separators when imports fail.
CSV Column Count
Quickly verify header width and row shape.

Workflows (kits)

CSV Debug Kit
Use CSV diagnostics before generating calendar files.