EpochDays

EpochDays

TIME, SIMPLIFIED.
Current UTC: --:--:--
Unix TS: 0000000000
Days: 00000
Tip: the URL updates as you type — copy it to share a pre-filled input (`?d=` or `?ts=`).
Start of Day (Unix Timestamp)
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Human Date (UTC)
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Days From Epoch (Floored)
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Human Date (Local)
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Quick Links

Code Examples

Popular Timestamps

Notable Dates

The Year 2038 Problem

Many operating systems and databases historically stored Unix time as a signed 32-bit integer: the number of seconds since the Unix Epoch. The largest value that fits is 2,147,483,647 seconds, which corresponds to 2038-01-19 03:14:07 UTC. One second later, the counter overflows and becomes negative, which can make clocks jump backward and cause sorting, expiration, and scheduling bugs.

Modern platforms typically use 64-bit time (or wider), pushing this limit far into the future. But embedded devices, legacy software, and long-lived infrastructure can still be affected—so it’s a useful sanity check when you’re converting timestamps or validating “seconds since 1970” fields.

Time remaining
4343d 6h 19m 54s
Target moment (UTC): 2038-01-19T03:14:08Z

Did you know? Leap seconds

Unix time (also called POSIX time) intentionally ignores leap seconds. It treats time as a simple count of SI seconds since 1970-01-01 00:00:00 UTC, without inserting the occasional extra second that UTC uses to stay in sync with Earth’s rotation. In practice, systems map this count to UTC using time zone databases and clock discipline (NTP), which is why edge cases like 23:59:60 are usually handled by “smearing” or stepping clocks rather than representing a literal leap second in Unix timestamps.

What is the Epoch?

The Unix Epoch is the reference point used by Unix time: 1970-01-01 00:00:00 in Coordinated Universal Time (UTC). A Unix timestamp is simply the number of seconds that have elapsed since that moment. If a timestamp is 0, it represents the Epoch itself. If it is 86400, it represents one day later. Negative timestamps represent moments before 1970.

Why 1970? Early Unix systems needed a single, consistent “day zero” to make file times, logs, and scheduling comparable across machines. The choice was partly practical: the date was close to the era when Unix was being developed, and it fit well within the limitations of the computers of the time. Using a recent baseline keeps timestamps smaller (fewer bits are needed to represent “now”), which mattered when memory and storage were expensive. It also avoided dealing with historical calendar reforms or dates far outside the expected operating range for early software.

This simple counter-based model is why Unix time is so useful for developers: it is time zone agnostic, easy to compare, easy to store, and easy to compute with. Convert local time to UTC, turn it into seconds since the Epoch, and you get a durable value that can be sorted, indexed, and transmitted between services. Tools like “days from epoch” are just a convenient re-scaling: divide seconds by 86,400 to get whole days since 1970 (useful for analytics buckets, partitions, retention windows, and daily rollups). The key idea stays the same: pick a common reference point, count forward in seconds, and you can represent time consistently across systems.

You’ll also see Unix time stored with more precision, such as milliseconds (ms) or nanoseconds, by counting smaller units since the same Epoch. That makes it practical for high-volume logs and distributed systems where many events occur within the same second. If you ever compare values across platforms, double-check the unit (seconds vs milliseconds) and whether the timestamp is UTC-based—because the Epoch itself is always defined in UTC, even if your app displays dates in a local time zone.