32-bit systems use four bytes, which mean they can use 4GB of memory in one go. By comparison, a 16-bit system uses two bytes and 64-bit systems use eight.
These systems store memory and carry out processes using binary digits, represented as 0 or 1 - and the total number of digits a 32-bit system can represent is 4,294,967,295.
But because half of the values are negative, and half are positive this doesn't range from zero up to 4,294,967,295.
Instead, the total numbers range from -2,147,483,648 to 2,147,483,647, thus making the upper limit of a 32-bit system 2,147,483,647.
This means there is only a limited amount of storage that can be used to store all the binary 0 and 1 numbers.
YouTube was set up on a 32-bit system and when Psy's Gangnam Style video reached this upper limit of views, the counter broke.
App users: Tap here to watch Gangnam Style
To solve the problem, Google updated the system to 64-bits, which can handle 9,223,372,036,854,775,807 views, or more than 9 quintillion.
At the time, Google said in a blog post: 'We never thought a video would be watched in numbers greater than a 32-bit integer (=2,147,483,647 views), but that was before we met PSY. "Gangnam Style" has been viewed so many times we have to upgrade!'
The standard four-byte format assumes the beginning of time is 1 January, 1970, at 12:00:00 a.m.
When the clock strikes 03:14:07 UTC on Tuesday, 19 January 2038, a total of 2147483647 seconds since 1 January 1970 will have passed.
Computers will then not be able to distinguish between the real time and date, and the year 1901.
This is called an 'integer overflow', and means the counter has run out of usable bits and begins reporting a negative number.
For some computers, this will simply mean the date is shown as incorrect, but it could equally wipe out computers and programs that rely on the internal clock to make precise measurements, for example.
It could also cause software to crash.
Many phones, for example, as well as flight systems and cars use embedded systems that rely on storing accurate times and dates.
In particular, the bug affects the Unix operating system, which powers Android and Apple phones, as well as most internet servers.
Some programs that work with future dates may also start experiencing problems sooner.
For example, a program that looks ahead 20 years will need to be fixed by 2018.
After 2018, it won't be able to register dates after 19 January 2038 and bugs may appear.
As Economist journalist Glenn Fleishman explained: 'Modern versions of the operating system have solved this problem by moving to a 64-bit signed integer to count seconds, but some ancient devices or those running ancient software may fail unpredictably.'
Affected systems will need to upgrade in order to avoid any problems.
How will the bug affect you?
Once the bug hits, affected computers will not be able to distinguish between the real time and date, and the year 1901.
For some computers this will simply mean the date is shown as incorrect, but it could equally wipe out computers and programs that rely on the internal clock to make precise measurements, for example.
It could also cause software to crash.
Many phones, for example, as well as flight systems and cars use embedded systems that rely on storing accurate times and dates.
Some programs that work with future dates may also start experiencing problems sooner.
For example, a program that looks ahead 20 years will need to be fixed by 2018. After 2018, it won't be able to register dates after 19 January 2038 and bugs may appear.
- Daily Mail
