Developer tools for everything time
Timestamps, time zones, cron schedules, recurrence rules — the parts of programming where everyone eventually loses an afternoon. These tools run entirely in your browser: nothing you paste is uploaded anywhere.
Epoch Auto-Detector
Paste any number — Unix seconds/ms/µs/ns, .NET ticks, Excel serial, FILETIME, NTP, Cocoa — and see what timestamp it is.
Cron Explainer
Cron expression to plain English, plus the next 10 run times in any IANA time zone, DST-aware.
ID Timestamp Extractor
Pull the creation time out of UUIDv1/v6/v7, ULID, MongoDB ObjectID, KSUID, and Twitter/Discord Snowflakes.
JWT Time Decoder
Decode a JWT and watch iat / nbf / exp as human dates with a live expiry countdown.
Date Format Detective
Paste a date string, get the matching format tokens for strftime, PHP, Moment/Day.js, Java, Go and .NET.
ISO 8601 Validator
Validate and dissect dates, times, durations (P1DT2H) and intervals. RFC 3339 compliance checked too.
RRULE Tester
Paste an iCalendar recurrence rule and see the next occurrences. “2nd Tuesday monthly”, solved.
ISO Week Numbers
Date ↔ ISO week conversion, week date ranges, and which years have 53 weeks.
What Does My Browser Think?
Locale, time zone, hour cycle, next DST change, clock skew vs server. Send this to users reporting “wrong time” bugs.
Log Timestamp Normalizer
Paste log lines with mixed timestamp formats and zones; get them aligned to one zone with deltas.
HTTP Caching & Backoff
Explain Cache-Control headers, compute freshness, parse Retry-After, and visualize retry backoff with jitter.
Year 2038 Countdown
Live countdown to the 32-bit time_t overflow, with the current epoch in binary. Tick tock.
AtlasClock developer tools cover the practical side of dates and times in software: converting epoch timestamps between encodings, debugging cron schedules and DST edge cases, validating ISO 8601 and RFC 3339 strings, decoding the timestamps embedded in UUIDs and Snowflake IDs, and understanding HTTP cache lifetimes. Free, no registration, no uploads.