Why does unix time start in 1970

But in some cases, a timestamp is more valuable. The problem refers to the time encoding error that will occur in the year in bit systems.

This may cause havoc in machines and services that use time to encode instructions and licenses. The effects will primarily be seen in devices that are not connected to the internet. This is what is know as the Unix Epoch. A timestamp is a sequence of characters or encoded information identifying when a certain event occurred, usually giving date and time of day, sometimes accurate to a small fraction of a second.

The UNIX timestamp is a way to track time as a running total of seconds. Skip to content Android Windows Linux Apple. Home » Other. This is already underway in most 64 bit Operating Systems but many systems may not be updated by Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group.

Create a free Team What is Teams? Learn more. Why does Unix time start at ? Ask Question. Asked 9 years, 11 months ago. Active 2 years, 2 months ago. Viewed 87k times. Why not or any other date? Improve this question. Templar Templar 1 1 gold badge 5 5 silver badges 13 13 bronze badges.

Add a comment. Active Oldest Votes. I wouldn't have known the answer except google was there for me: From Here needs free subscription : Linux is following the tradition set by Unix of counting time in seconds since its official "birthday," -- called "epoch" in computing terms -- which is Jan. Improve this answer. Hanan N. See stackoverflow.

Unix isn't born in Danny A Danny A 1 1 silver badge 2 2 bronze badges. Convenient back then, inconvenient for developers the world over ever since. ChrisHalcrow: what would you have chosen as time 0 if you were dmr?

And how is the choice inconvenient for developers? Not sure why anyone thought this was subjective. Today it was , hours ago — mplungjan. We should start counting time since this date, so we are now on year Today, right now, it is !

Its just approx. LeonardoRaele Yeah! Show 2 more comments. Active Oldest Votes. Improve this answer. It's the frequency of one of the oscillators on the system boards used at the time. It wasn't necessary for the oscillator to be 60Hz since it ran on DC, but it was probably cheap to use whatever was most common at the time, and TVs were being mass-produced then Actually, at the time, it was very common for computer clocks as well as RTCs to be synchronised with the US mains waveform because it was is?

It was multiplied to get the processor clock, and divided to get seconds for the RTC. JediKnight This is speculation based on my own experiences as a developer: changing a standard takes time, and if your change doesn't take hold then you end up with competing standards.

The real solution to the epoch problem is bit integers, not moving the epoch forward in time. Show 15 more comments. Epoch time is 1 January , not 1 January SteveHarrison It is, but it didn't start out that way — Reid. Add a comment. Notable excerpts from the Wikipedia page: The first edition Unix Programmer's Manual dated November 3, defines the Unix time as "the time since , Jan.

Epoch reference date An epoch reference date is a point on the timeline from which we count time. Many epochs in use Why is 1 January considered the epoch time? No, not the epoch, an epoch. There are many epochs in use. This choice of epoch is arbitrary. Many granularities Different systems use different granularity in counting time. ISO Because there is so much variance in the use of an epoch reference and in the granularities, it is generally best to avoid communicating moments as a count-from-epoch.

Short answer: Why not? There's no great merit in choosing an arbitrary epoch just to be different. Because Unix was developed in and first released in and it was thus reasonable to assume that no machine would have to represent a system time earlier than