Longword

A longword, or doubleword, is a set of computer data, 32 bits long, that is processed as a unit. A word is half as long at 16 bits.
==Date longwords==
Early Macintosh systems support 32-bit date longwords, which count the seconds passed since January 1, 1904 (1900 was not selected because it is a century year). This value could be reset if the system undergoes a serious crash or if the clock battery dies while the power is out.Why Do Older Macs Reset to 1904? by Jeff Adkins, Low End Mac. 2004-01-15. The 32-bit date value will run out and reset on February 6, 2040 on Macs using drives formatted with HFS or HFS Plus.Solving Mac OS 8’s Y2K20 Bug by Josh Centers, TidBITS. 2020-01-03.
Mac OS X systems start counting from January 1, 1970. Because the data is counted differently, versions prior to 10.6 will run out on January 19, 2038, a limitation inherited from Unix.Is any version of OS X/macOS vulnerable to the Year 2038 problem? by Thunderforge, Stack Exchange. 2016-09-13. Starting with the Apple File System, introduced in 2017 with macOS 10.13, date values are stored as 64-bit quadwords, which support dates through July 21, 2554.Decoding the APFS file system by Kurt H. Hansen and Fergus Toolan, Norwegian Police University College. 2017-04-22. Revised 2017-06-21.
==References==
==External links==
*Doubleword and longword at Wiktionary
Category:Technical terminology