getUTC

get the current time in UTC

getUTC documentation

Table of contents

• Description section:
• • Description
• Matlab/Octave section:
• • Syntax
• • Output arguments
• • Compatibility, version info, and licence

Description

For some applications it is necessary to know the current UTC time. This function has three methods to determine the UTC timestamp: an implementation written in C (which will be compiled), a call to a website, and a system call.

There are several methods implemented in this function:

• An implementation that requires a C mex function (which will be compiled).
  This method requires write access to a folder and a working C compiler. The compilation result will be stored to a subdirectory of a folder similar to the AddOn path, or the tempdir, or the current folder. Write permission is tested in that order.
• An implementation using https://www.utctime.net/utc-timestamp.
  The NIST has a server that returns the time, but it currently blocks API access, hence this replacement.
  This method requires internet access.
• The local time and timezone offset can be determined with the wmic command or the get-date Powershell function (Windows) or the date command (Linux and Mac).
  On Windows an NTP query is also implemented (internet connectivity is checked prior to this call).

To speed up the usage of this method, you can cache the difference with now() in a persistent variable, that way you avoid the need for a slow system call.

Matlab/Octave

Syntax

atomTime = getUTC

Output arguments

Argument	Description
atomTime	The current UTC in the numeric format produced by datenum. Depending on which method is used, the accuracy may be reduced by longer execution times (up to a second).

Compatibility, version info, and licence

Compatibility considerations:

• Some older releases don't support the web implementation.
• The normal system call hangs on ML7.1 on XP. Since ML6.5 works fine on Windows 10, it seems reasonable to assume that the OS is the cause of the hang. For XP (and older) there is an alternative strategy in place, but this has a higher likelihood to fail.
• Similarly, as wmic has been deprecated, a Powershell alternative should be used on newer versions of Windows. The need for this is automatically detected.

Test suite result	Windows	Linux	MacOS
Matlab R2023b	W11 : Pass	ubuntu_22.04 : Pass	Monterey : Pass
Matlab R2023a	W11 : Pass	ubuntu_22.04 : Pass
Matlab R2022b	W11 : Pass	ubuntu_22.04 : Pass	Monterey : Pass
Matlab R2022a	W11 : Pass
Matlab R2021b	W11 : Pass	ubuntu_22.04 : Pass	Monterey : Pass
Matlab R2021a	W11 : Pass
Matlab R2020b	W11 : Pass	ubuntu_22.04 : Pass	Monterey : Pass
Matlab R2020a	W11 : Pass
Matlab R2019b	W11 : Pass	ubuntu_22.04 : Pass	Monterey : Pass
Matlab R2019a	W11 : Partial
Matlab R2018a	W11 : Partial	ubuntu_22.04 : Partial
Matlab R2017b	W11 : Partial	ubuntu_22.04 : Partial	Monterey : Partial
Matlab R2016b	W11 : Partial	ubuntu_22.04 : Partial	Monterey : Partial
Matlab R2015a	W11 : Pass	ubuntu_22.04 : Pass
Matlab R2013b	W11 : Partial
Matlab R2007b	W11 : Partial
Matlab 6.5 (R13)	W11 : Partial
Octave 8.2.0	W11 : Pass
Octave 7.2.0	W11 : Pass
Octave 6.2.0	W11 : Pass	ubuntu_22.04 :	Catalina :
Octave 5.2.0	W11 : Pass
Octave 4.4.1	W11 : Pass		Catalina :

Version: 2.2.0
Date:    2023-11-21
Author:  H.J. Wisselink
Licence: CC by-nc-sa 4.0 ( https://creativecommons.org/licenses/by-nc-sa/4.0 )
Email = 'h_j_wisselink*alumnus_utwente_nl';
Real_email = regexprep(Email,{'*','_'},{'@','.'})

Test suite

The tester is included so you can test if your own modifications would introduce any bugs. These tests form the basis for the compatibility table above. Note that functions may be different between the tester version and the normal function. Make sure to apply any modifications to both.