Json Date Formatter
Parse Microsoft /Date(ms)/ and JSON ISO date strings into readable timestamps. Free JSON date formatter for APIs and legacy .NET web payloads.
How to Use
- Paste a JSON date value-/Date(ms)/ or a quoted ISO string.
- Click Format JSON date to parse and display.
- Read local time, UTC, and detected format in details.
- Copy readable output into bug tickets or documentation.
- Try both formats side by side when migrating APIs.
Input Field Guide
- JSON date value
- Microsoft /Date(1700000000000)/ or ISO string like "2026-07-13T10:30:00.000Z" from JSON payloads.
Understanding Your Results
The formatter identifies whether input matches /Date(ms)/ or ISO JSON string patterns, then shows human-readable local date-time plus epoch milliseconds for cross-check. Unknown shapes produce a helpful error instead of silent mis-parsing.
Features
- Microsoft /Date(ms)/ support
- ISO JSON string support
- Automatic format detection
- UTC and local display
- Millisecond echo for verification
- Private local parsing
Formula & Calculation Logic
/Date(ms)/ -> extract integer ms; ISO -> Date.parse; display via local timezone formatting.
Real-World Use Cases
- Legacy ASP.NET Web API debugging
- Silverlight and old SharePoint timestamps
- Mixed-version API migration testing
- DevTools network tab date inspection
- Support ticket payload clarification
Practical Examples
/Date(1700000000000)/ -> readable instant with ms echoed.
"2026-07-13T10:30:00.000Z" -> parsed Zulu JSON string to local.
Benefits
- One box for two common JSON date shapes
- Avoids regex mistakes extracting milliseconds
- Keeps customer payloads private
- Faster than spinning up a REPL
Tips & Best Practices
- Include quotes for JSON string values when copying literally.
- Use iso-converter for bare ISO without JSON quoting.
- Use unix-timestamp-converter for raw numeric epochs.
Common Mistakes to Avoid
- Pasting entire JSON objects instead of the date value field.
- Dropping timezone from ISO strings then blaming the parser.
- Expecting named timezone conversion-use timezone calculator.
Frequently Asked Questions
What JSON date formats are supported?
Microsoft /Date(milliseconds)/ and standard quoted ISO 8601 strings.
Can I paste the whole JSON object?
Paste the date value itself; whole objects may fail detection.
How is this different from iso-converter?
JSON formatter handles /Date(ms)/ plus JSON-quoted ISO; iso-converter targets bare ISO strings.
Are negative /Date/ values supported?
Yes within JavaScript Date limits for pre-1970 instants.
Does it escape strings for output JSON?
It focuses on human-readable display, not re-serialization.
Will single quotes work?
Prefer double quotes matching JSON; detection expects JSON conventions.
What if both patterns appear?
Detection picks the best match; invalid hybrids show errors.
Is JSON uploaded for formatting?
No. Parsing runs locally.