SmartQueryTools

Parse Dates in CSV Files Online

Parse and convert date columns in CSV files between formats and timezones directly in your browser. Supports ISO 8601, US/EU dates, Unix timestamps, and custom patterns — no upload required.

How to parse Dates in CSV files

  1. Drop your file. The first column is preselected, and the output name defaults to that column name plus _parsed.
  2. Pick the column to parse. The list shows each column's detected type, so you can see whether it is already a DATE or TIMESTAMP or still text.
  3. Choose the input format: Auto-detect, ISO 8601, US date (MM/DD/YYYY), EU date (DD/MM/YYYY), Unix epoch in seconds or milliseconds, or a custom strptime pattern.
  4. Leave both timezones on UTC unless you need a conversion, then pick an output format: ISO 8601, date only, US date, EU date, Unix epoch seconds, or a custom strftime pattern.
  5. Click Parse Dates, check the preview, and download. The parsed column replaces the original column in the same position. A message tells you how many values could not be parsed.

Your file is processed locally in your browser and is never uploaded. The free limit is 50 MB per file; larger files work if your device has the memory for them.

Worked example

A hotel booking system exports check-in times as ISO-style timestamps. The UK finance team wants plain DD/MM/YYYY dates, and one booking still has "TBC" instead of a date.

Input (CSV)

booking_ref,guest_country,check_in,nights
HB-5520,IE,2026-09-14 15:00:00,3
HB-5521,DE,2026-09-15 11:30:00,1
HB-5522,FR,TBC,2
HB-5523,GB,2026-10-02 18:45:00,5

Settings

  • Column to parse: check_in
  • Output column name: check_in_parsed (the default)
  • Input format: Auto-detect
  • Source and target timezone: UTC (no conversion)
  • Output format: EU date (15/01/2024 style)

Result

booking_refguest_countrycheck_in_parsednights
HB-5520IE14/09/20263
HB-5521DE15/09/20261
HB-5522FRNULL2
HB-5523GB02/10/20265

check_in is replaced by check_in_parsed in the same position, and the other columns are untouched. Auto-detect reads the timestamps and the EU output keeps only the date. "TBC" is not a date, so it becomes NULL instead of stopping the run, and the tool reports 1 value that could not be parsed. The new column is text, because DD/MM/YYYY is a display format rather than a date type.

Working with CSV files

The CSV reader tries to recognise dates while it loads the file. A column of values such as 2026-09-14, or even 14/09/2026, is often already a DATE by the time you see it, and the column list shows that type. A column that is already DATE or TIMESTAMP is used as it is, whichever input format you pick, so the US, EU and custom modes also work on it. Only the output format matters then.

Columns that mix formats, or hold words such as TBC or pending, stay as text. Pick the mode that fits most values. Values that do not fit become empty, and the tool tells you how many. The parsed values are written into the CSV as plain text in the format you chose, and epoch seconds output is written as a whole number. Nothing in a CSV marks a column as a date, so the next program that opens the file will guess the type again.

Frequently Asked Questions

Does EU date mode work if the CSV reader already typed the column as DATE?

Yes. A DATE or TIMESTAMP column is used directly, whatever input format you pick. Choose the output format you want, such as EU date.

Which output format should I pick if the CSV will be opened in Excel?

ISO 8601 or date only (2026-09-14). Excel reads that form as a date in almost every locale. DD/MM/YYYY and MM/DD/YYYY can be swapped or left as text depending on the regional settings of the computer opening the file.

What happens to values that cannot be parsed?

They become empty (NULL) in every mode, and the rest of the column is parsed. After the run the tool tells you how many values failed, so you can check them. Empty cells are not counted as failures.

How does the time zone conversion work?

The source zone is where the times were recorded, and the target zone is the one you want. 14:00 US/Eastern in July becomes 18:00 UTC, and 14:00 in January becomes 19:00 UTC, because daylight saving time is applied. Unix epoch values are always read as UTC, whatever the source zone says.

Does the tool keep the original column?

No. The parsed values replace the source column in the same position, under the output column name. Keep a copy of the original file if you need both.

What type is the parsed column?

Text for every output format except Unix epoch seconds, which is a whole number. ISO 8601 output looks like 2026-09-14T15:00:00 and date-only output like 2026-09-14. Cast the column to DATE or TIMESTAMP afterwards if you need a typed column.

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