Date to Hex Converter
Convert a date and time into its hex Unix timestamp — the compact format many file systems and binary logs store dates in.
Built by
Swapnil SanghviFull-Stack Web Developer & WordPress Developer
Swapnil Sanghvi is a full-stack web and WordPress developer, UI designer, and full-time freelancer who builds and maintains Hex Calculator.
Further reading: Unix time — Wikipedia
How to Convert a Date to Hex
First convert the date to a Unix timestamp — the whole number of seconds between midnight UTC on January 1, 1970, and the given date and time. Then convert that decimal number of seconds into hexadecimal, the same way any decimal number converts to hex.
Date to Hex Example, Step by Step
2024-01-15 10:30:00 UTC = 0x65A50928
2024-01-15T10:30:00Z -> 0x65A50928
2024-01-15 10:30:00 UTC = 1,705,314,600 seconds after 1970-01-01 00:00:00 UTC = 0x65A50928
| Step | Description | Result |
|---|---|---|
| Compute seconds since epoch | 2024-01-15 10:30:00 UTC = 1,705,314,600 seconds after 1970-01-01 | 1,705,314,600 |
| Convert to hex | 1,705,314,600 in base 16 | 0x65A50928 |
This is the same calculation your operating system does internally whenever it stores or compares a file's modification time.
Where Date to Hex Actually Comes Up
Writing a Timestamp Into a Binary File Format
Constructing a binary file or protocol frame by hand (for testing or reverse engineering) often means writing a specific date as a raw hex timestamp field.
target date -> hex value to write
Setting Up a Test Fixture With a Known Timestamp
Testing code that reads a hex-encoded timestamp is easier with a predictable input — converting a chosen test date to hex gives you an exact, reproducible fixture value.
fixed test date -> hex fixture value
Cross-Checking a Y2038 Boundary Case
Verifying how code handles dates near the 32-bit timestamp limit means generating the hex value for a date right at or past January 19, 2038 to use as a test case.
2038-01-19 -> boundary test value
Why Use This Calculator Instead of Doing It by Hand
- Handles the date-to-timestamp math and decimal-to-hex conversion in one step
- Always interprets input as UTC, avoiding timezone-dependent results
- Runs entirely in your browser — nothing you type gets sent anywhere
- Accepts either a date alone or a full date and time
Limitations
- Only supports dates on or after January 1, 1970 (UTC) — earlier dates aren't supported since this tool doesn't assume a specific negative-timestamp encoding.
- Truncates to the whole second — sub-second precision in the input isn't preserved.
Frequently Asked Questions
What date format does this expect?
ISO 8601 style — a date alone like 2024-01-15, or a date and time like 2024-01-15T10:30:00Z. If you don't include a timezone, the date is treated as UTC, not your local timezone.
How is the date converted to hex?
The date is converted to a Unix timestamp (whole seconds since January 1, 1970, UTC), then that number is converted to hexadecimal.
Why does the result use 8 hex digits?
8 hex digits (32 bits) is the classic Unix timestamp width — this converter pads shorter results to 8 digits to match that common format, though the underlying value isn't limited to 32 bits.
Can I convert a date before 1970?
No — dates before the Unix epoch (January 1, 1970 UTC) aren't supported here, since representing a negative timestamp in hex would require choosing a signed encoding convention this tool doesn't assume.
Does the time of day matter, or just the date?
Both — if you only enter a date (like 2024-01-15), it's treated as midnight UTC on that date; include a time (like 2024-01-15T10:30:00Z) for a specific moment.