UNIX time is the system that computers used to measure time. But how does UNIX time work? And what is a “UNIX Epoch”?
What is the era? What is the Y2038 problem?
It’s so popular that you probably use it without your knowledge. However, once you understand UNIX time, you can find it in many situations. Some tools help you work in UNIX time.
What is the purpose of UNIX time?
UNIX time is the total number of seconds since a fixed date and time. This is a date/time (or timestamp) format that looks different from human-readable dates and times. This is purely for efficiency reasons. It takes much less space to store a single number of seconds than to store individual values such as year, month, and hour.
Of course, in modern terms, the difference in space isn’t that big. But think of UNIX as it started in the late 1960s when the available storage was much smaller. Timestamps are also used frequently, so their storage is totaled.
Unless you’re a math genius, it’s almost impossible to translate a format in your head. However, there are still some advantages over the more readable alternatives, such as Wednesday, October 21, 2015, at 07:28:00 GMT. At a glance, you can order two UNIX time stamps very easily. Also, it is usually quicker to understand the difference between the two timestamps. This is especially true when the dates are close, such as adjacent days.
Therefore, UNIX time converter is the total number of seconds since a certain time. But what are the points? It is UTC 00:00:00 on January 1, 1970. This is often referred to as a UNIX era. The programmer can choose this date for the sake of simplicity more about it because it was the date of the next round when he invented the UNIX era.
You may have seen this date when something went wrong. Obviously a bug, but it looks very strange when it comes to dates before many people were born. However, if you know about UNIX time, you can fully understand it. When the system tries to display timestamp with no value, it is often converted to 0, which is the exact epoch date.
UNIX time data format
Strictly speaking, there is no one. The original data type was a 32-bit integer, but this is often the case even on much more powerful systems. This data type can be used to store a total of 2 ^ 32 seconds in a value. This is over 136 years. This value is usually signed. That is, it can be a negative or positive value. Therefore, it usually represents 68 years on both sides of the epoch, namely 1902-2038.
Of course, this is still a limited time. However, the main use of the timestamp format was for concepts such as changing files. It needed to represent time closer to the present, not ancient history or the distant future. Even for applications such as calendars, it is unlikely that you will need to represent a date that is more than a few decades away.
But that doesn’t mean it is okay for this limited period…
The year 2038 problem
The Y2K bug (one of the worst programming mistakes in history) has affected computer systems that store years as double-digit values. In 2000, such a system was treated like 1900. In this case, this was not horribly devastating, mainly because many people spent a lot of time and effort preparing in advance.
If you paid attention to it in the previous section, you may have found a similar issue that could affect UNIX time. Well, UNIX time has its own data problem: the Y2 k38 problem. (This is often referred to as a problem rather than a bug. It may be optimistic since 2000!) When UNIX time literally runs out in 2038, the system treats the new date as 1902 or 1970 increase it fails completely.
At least, this problem doesn’t occur on New Year’s Eve midnight strokes. The last second of 32-bit UNIX time is March 19th. Eventually, most systems may be upgraded by 2038, or in any case obsolete.
Some useful timestamp resources
The epoch converter site is probably the most comprehensive timestamp converter. First, it displays the current UNIX time in real-time and adds almost all possible features on top of it. Its main use is to convert time stamps and human-readable dates in both directions.
Dan’s Tools is a collection of a large number of useful web applications, one of which is a timestamp converter. It is more basic but easy to use, and the presentation is very clean time presents another, more minimalist look. Displays time in many formats, including UNIX time. This is useful because the page title contains the current time.
Use UNIX Time in Command Line Tools
On Linux, the dating software is a key tool for managing dates/times (including UNIX timestamps). When called without parameters, it returns the current date/time in a readable format.
How to use UNIX time in a programming language
PHP has a time () function that returns the current UNIX timestamp. The date () function takes a timestamp as the second argument.
Understand UNIX time
UNIX time is a simple concept found in many places understanding that can be very helpful, for example, when calculating the time difference. You can also recognize if it could be the cause of a particular bug.