1. Parse your data
Pick one timestamp per line, or choose a CSV delimiter and header setting. Quoted fields, embedded newlines and escaped double quotes are supported. Empty data records remain visible.
MANY ROWS. ONE EXPLICIT TIME FORMAT.
Batch TimestampConverter.
Turn a whole column into usable time. Convert CSV files or pasted lists, keep every original row, and take the complete result with you.
Build your conversion
01
Bring your rows
Paste text or import a UTF-8 .txt or .csv file.
Original cells stay unchanged in the preview.
02
Choose what time means
Parse first, then choose the timestamp column and its exact format.
Columns are numbered, including empty or duplicate headers.
Seconds may have up to 3 decimal places. Example: 1704067200.125. Scientific notation and automatic unit detection are not used.
UTC or an IANA zone name. This only changes the zoned display; the UTC instant stays the same.
Limits: 5 MiB UTF-8 text, 10,000 data records, 1,000 columns. Surrounding ASCII whitespace is trimmed for conversion only.
Every row accounted for.
Original columns + UTC, epoch and zoned results. Invalid records stay in place.
Preview: up to 50 rows per page, fewer for wide files. Long cells are shortened at 400 characters and headers at 90. Full original values are retained and exported.
TOTAL RECORDS0
VALID0
ERRORS0
Your batch result will appear here.
Parse the source, choose a column, and convert. Downloads always include all converted rows, not just the visible page.
Export the whole batch.
Adds an apostrophe to risky original values, headers and derived text such as UTC offsets in CSV and TSV. Unix seconds/milliseconds are not prefixed; preview cells remain exact. Exported text changes, and no protection is universal across spreadsheets or after saving and reopening.
Original-value export is on. Original cells are exported without added apostrophes. Formula-like text can execute in spreadsheet apps. Only open trusted data.
One clear path from source to result.
2. Declare the format
Choose one column and one input format for the whole batch. Seconds and milliseconds are never guessed. Strict ISO input must include Z or a numeric offset.
3. Keep every outcome
Review successful rows and clear error messages side by side. Change an input to invalidate results, then rerun. Export includes every original column and every data row.
Details that matter
Which ISO date-time strings are supported?
This tool supports a deliberately strict subset: four-digit year, full date, uppercase T, hours, minutes, seconds, optional 1–3 fractional digits, and uppercase Z or ±HH:mm. The UTC result must be in years 0000–9999. It rejects offset-free times, leap seconds, 24:00, rollover dates, greater-than-millisecond precision and the unsupported unknown-local-offset notation −00:00. It does not claim complete ISO 8601 or RFC 3339 support.
How are time zones and daylight saving handled?
An epoch value or an explicit-offset ISO date-time identifies the instant. The browser’s time-zone database formats that instant in your chosen IANA zone, including the applicable offset. No offset-free local input or ambiguous daylight-saving time is guessed. Historical results can vary with browser and time-zone database version.
What happens to CSV headers, errors and empty rows?
The header checkbox explicitly controls the first record. Choose the delimiter; it is never guessed. Original imported cell text is preserved, including embedded CRLF. Editing or pasting in the text box uses the browser’s normalized line endings. Quoted multiline cells and doubled quotes are supported, and a final line ending is not an extra record. Ragged records are padded in the preview and export. Conversion errors stay alongside their original rows. This is a practical CSV dialect based on RFC 4180, with selectable delimiters.
Why can a spreadsheet-hardened export change my values?
Spreadsheet applications may interpret text beginning with formula characters as commands. The default export prefixes risky original values, headers and derived text (such as signed UTC offsets) with an apostrophe. Known numeric Unix seconds/milliseconds are not prefixed. Uncheck it only when exact-value export is more important and you understand the risk. Both CSV and TSV use this choice. No mitigation is universal, especially after a spreadsheet saves and reopens a file.
Are my files uploaded, saved or remembered?
No. Parsing, conversion and exports run locally in this browser page, without analytics, network requests for your data, local storage or cookies. Refreshing, navigating away or closing the page clears the working data. Switching EN / 中文 within this page preserves your input and completed result; it cancels any in-progress work.