Detect and convert mixed date formats (MM/DD/YYYY, DD-Mon-YY, natural language) to ISO-8601 YYYY-MM-DD in Excel. Browser-only.
Free is enough for most one-off jobs. Pro raises the file and batch caps; Pro + Media unlocks GB-scale streaming and unlimited duration.
Larger files supported on Developer (5 GB CSV) and Enterprise (unlimited). All processing happens in your browser — files never reach a server.
Upload your Excel or CSV file with mixed date columns
Select the target date column — chrono-node detects formats automatically
Download the file with all dates converted to YYYY-MM-DD
0 bytes uploaded. Date Standardizer runs entirely in your browser using SheetJS and ExcelJS. Your spreadsheets never leave your device.
chrono-node recognises MM/DD/YYYY, DD/MM/YYYY, DD-Mon-YYYY, YYYY-MM-DD, natural language ('Jan 5 2024'), and Unix timestamps.
Unparseable values are left unchanged and flagged in the result report so you can review them manually.