Unix Timestamp Converter
Free Unix Timestamp Converter. Convert Unix timestamp to date/time and date/time to Unix format with UTC/local display and block-time estimates.
Enter timestamp or date
Use Unix seconds/milliseconds or a date time value to convert instantly.
How to use Unix Timestamp Converter
The Timestamp Converter translates between Unix timestamps (seconds since January 1, 1970 UTC) and human-readable date/time formats. Blockchain data universally uses Unix timestamps — every transaction, block, and smart contract event stores time as a Unix integer. This calculator makes those timestamps immediately interpretable.
Use it when analyzing blockchain data in explorers, reading smart contract logs, or debugging transaction history exports. Paste a Unix timestamp from Etherscan, a DeFi contract, or a CSV export and instantly see the corresponding date and time in your local timezone or UTC.
Input guide and assumptions
Enter a Unix timestamp (integer seconds) to get the human-readable date and time, or enter a date and time to get the corresponding Unix timestamp. The calculator supports timestamps in both seconds (10 digits) and milliseconds (13 digits) — common in JavaScript-based applications and some exchange APIs.
The output displays time in UTC and optionally in your browser's local timezone. For smart contract interactions, Solidity uses seconds-based Unix timestamps while JavaScript uses milliseconds — dividing a 13-digit timestamp by 1,000 converts it to seconds format. The calculator auto-detects the format based on the input length.
How to interpret results correctly
The Unix timestamp converter translates between human-readable dates and Unix epoch timestamps used by blockchain systems. Every blockchain transaction, block, and smart contract event is recorded with a Unix timestamp — the number of seconds elapsed since January 1, 1970 UTC. Converting these timestamps to readable dates is essential for verifying transaction timing, analyzing on-chain activity patterns, and reconciling blockchain data with real-world events.
Blockchain-specific timestamp considerations include that different chains use different precision levels: Ethereum uses seconds, while some chains use milliseconds. Smart contract developers must handle timestamp comparisons carefully — block timestamps can vary by up to 15 seconds from wall-clock time on Ethereum, which affects time-dependent contract logic like auction deadlines, vesting cliff dates, and governance proposal expiration.
Common mistakes to avoid
- Treating blockchain timestamps as perfectly accurate real-world clocks. Block timestamps can be manipulated within limits by miners/validators and may differ by seconds to minutes from actual wall-clock time.
- Using the wrong timestamp precision. Some APIs return Unix timestamps in seconds, others in milliseconds. A millisecond timestamp interpreted as seconds produces a date thousands of years in the future — a common bug in blockchain integrations.
Authoritative sources
Frequently asked questions
What is a Unix timestamp converter?
A Unix timestamp converter translates between Unix epoch seconds (e.g., 1735689600) and human-readable UTC datetime (2026-01-01 00:00:00 UTC). Every Ethereum block, Bitcoin tx, and oracle update is timestamped in Unix seconds.
How do I convert a Unix timestamp?
Divide by 86,400 to get days since 1970-01-01, then add to the epoch date. Most blockchain explorers do this automatically. Example: 1727740800 = 2024-10-01 00:00:00 UTC. JavaScript: new Date(1727740800 * 1000).toISOString().
Why are blockchain times in Unix epoch?
Unix timestamps are timezone-agnostic, monotonically increasing, and fit in a 32-bit (until 2038) or 64-bit integer. This avoids leap-year, DST, and locale bugs that plague human date strings — every node on Earth agrees on the same number.
Seconds vs milliseconds — which does my chain use?
Bitcoin and Ethereum use seconds (10-digit numbers like 1735689600). JavaScript Date.now() and many APIs use milliseconds (13-digit, e.g., 1735689600000). If your timestamp is from 1970 or year 53,000, you mixed the units — divide or multiply by 1,000.
What is the Year 2038 problem?
Signed 32-bit Unix timestamps overflow at 03:14:07 UTC on 19 Jan 2038. Bitcoin's block headers use uint32 timestamps (overflow in year 2106), but most modern blockchains and wallets use 64-bit integers and are safe past year 292,000,000,000.
How do I find the timestamp of an Ethereum block?
Use Etherscan: enter the block number, look at "Timestamp" (shows both UTC and Unix). Programmatically: web3.eth.getBlock(blockNumber).timestamp returns Unix seconds. Block 21,500,000 was mined on 2025-01-08 04:35:35 UTC = 1736310935.
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