Truncate Dates in CSV Files Online

What does truncating a date to month mean in a CSV file?

It sets the timestamp to midnight on the first day of that month. For example, 2024-03-15 09:45:22 becomes 2024-03-01 00:00:00. The date_trunc function rounds down, never up.

Can I truncate a text date column in a CSV file?

Yes. The tool automatically casts text columns to TIMESTAMP before truncating using TRY_CAST. If any values cannot be parsed as dates, those rows will return NULL in the output. Use the Date Parse tool first if you need to standardise the format.

What is the difference between date truncation and date formatting in a CSV file?

Truncation changes the underlying date value — it rounds it down to the nearest period. Formatting only changes how the date is displayed as text without altering the value. Use truncation when you want to group timestamps into buckets for aggregation or filtering.

Is my data private?

Yes — completely. Your file is never uploaded to any server. Everything runs locally in your browser using WebAssembly — processing happens entirely inside your tab. Once you close the tab, nothing is retained.

What is the maximum file size?

The free limit is 50 MB. For larger files, performance depends on your device's available memory — most modern machines handle 500 MB to 1 GB comfortably.