One incident timeline routinely mixes three formats: epoch seconds from a backend log, epoch milliseconds from a JavaScript client, and an ISO string from a managed service.
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Timestamp Converter
Unix timestamp or date string
Free · API · MCPToolYour platform
Use Timestamp Converter three ways
The free Timestamp Converter on this page works in your browser. The same workflow is available via REST API for apps and via MCP for Cursor, Claude, and other agents — one API key, one plan, one quota. This tool is part of the developer-apis module under Developer Tools.
- Free in browserUse Timestamp Converter here — no account required.
- REST APICall from your server with
X-Api-Key. - MCP for agentsConnect Cursor or Claude to ToolYour MCP with the same key.
- 1. Get an API keySign in and open Dashboard → API Keys (works for REST and MCP).
- 2. Call or connectUse the REST API from your server, or paste the MCP URL into your agent config.
- 3. Same qualityOutput matches the free web tool across all three surfaces.
What is Timestamp Converter?
One incident timeline routinely mixes three formats: epoch seconds from a backend log, epoch milliseconds from a JavaScript client, and an ISO string from a managed service. This timestamp converter takes any of them and returns all of them at once — ISO 8601, Unix seconds, Unix milliseconds, an RFC-style UTC string, and a host local rendering for a quick sanity check.
Numeric input is disambiguated by magnitude: values below one trillion are read as seconds, larger values as milliseconds, which is the convention that matches real logs. Anything that cannot be parsed into a date fails with an error rather than silently becoming the epoch. Timezone handling stops at UTC plus the local hint — this is not an IANA timezone engine, so daylight-saving arithmetic and scheduling across zones belong in a real date library. When you need matching identifiers for the same fixture, UUID Generator is the companion call.
Browser use is free and needs no signup. The same job runs over REST at POST https://api.toolyour.com/api/v1/developer-apis/timestamp-converter and over MCP at https://api.toolyour.com/mcp — one API key, one shared monthly credit pool, 1 credit per successful call.
What are common questions about Timestamp Converter?
How does it know seconds from milliseconds?
By magnitude. Numeric input below one trillion is treated as seconds; anything larger is treated as milliseconds, matching how real logs are written.
Does it handle named time zones?
No. Output is ISO and UTC plus a host local hint. For IANA zone conversions and daylight-saving rules, use a proper date library.
What input formats are accepted?
Epoch seconds, epoch milliseconds, and date strings the platform date parser understands, including ISO 8601 and RFC 2822 forms.
What are the key features of Timestamp Converter?
Every format in one response
ISO, epoch seconds, epoch milliseconds, UTC string, and a local hint together.
Magnitude-based detection
Seconds and milliseconds are distinguished automatically, so you can paste and go.
Errors instead of epoch zero
Unparseable input fails clearly rather than quietly returning 1 January 1970.
How do you use Timestamp Converter?
Paste the value
An epoch number from a log or a date string from an API response.
Read across formats
Use the ISO or UTC output when correlating events between systems.
Copy what you need
Paste into a fixture, a query filter, or an incident timeline.
Correlating logs that disagree about time
The usual failure in an incident timeline is not a wrong clock, it is a mixed unit. A backend writes epoch seconds, a browser writes
Date.now() in milliseconds, and a managed service writes ISO strings with an offset. Placed on the same timeline without conversion, events appear a thousandfold apart or in the wrong order.
The safe habit is to normalise everything to UTC ISO before comparing. It sorts lexicographically, it carries no ambiguity about zone, and it is readable in a ticket. Convert once at the boundary rather than reasoning about offsets in your head at three in the morning.Timestamps in the wider toolset
Timestamps show up across this category. [Cron Expression Parser](/developer-tools/cron-expression-parser) reports next run times in UTC, so converting your local target time here first tells you whether a schedule really fires when you expect. [UUID Generator](/developer-tools/uuid-generator) can produce time-ordered identifiers for the same fixture.
When a token expiry is the question, decode the token with the Security Tools JWT Decoder and paste its
exp claim here — expiry claims are epoch seconds, and reading them as milliseconds is a classic source of "the token never expires" confusion.Which core developer tools sit in this cluster?
Where do you browse more developer tools tools?
- Developer Tools tools
Browse the full Developer Tools category on ToolYour.
- Marketing Tools tools
Build UTM links, check ads copy limits, QA email subjects, and calculate ROAS/CPC/CTR — free in the browser; R
- Security Tools tools
Check HTTP security headers, TLS, cookies, JWTs, passwords, hashes, and SPF/DKIM/DMARC — free in the browser;
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