About the date format and how to change it

The date format determines how dates are displayed throughout the AVEVA Edge software, as well as how date strings are handled by the project during run time. You can change the date format, either as part of localizing your project or simply to suit your personal preference.

Actual dates and times are stored as complete timestamps, the format of which is hardcoded into the software. Such timestamps can be difficult to read, however, and they often contain additional information that is not immediately relevant to the user. Therefore, when it is necessary to display a date and/or time, the software parses the timestamp, gets the relevant information, and displays it in a user-friendly format. The date format determines what exactly that format is for dates.

Generally speaking, the date format has two configurable settings: the order and the separator. First, the order setting determines the order in which the day (D), month (M), and year (Y) are displayed. Any combination of the three can be used, but some combinations like MDY, YMD, and DMY are more commonly used. Second, the separator setting determines the character that separates the three parts of the date. Again, any single character can be used, but some characters like the forward slash (/), the hyphen (-), and the dot/period (.) are more commonly used.

The order and separator settings together determine the overall date format. For example, AVEVA Edge uses the MDY order and the forward slash (/) separator by default, and together they produce the American-style format MM/DD/YYYY (such as 02/13/2015). Another common date format is the one recommended by ISO 8601; it uses the YMD order and the hyphen (-) separator to produce the format YYYY-MM-DD (for example, 2015-02-13).

Note: AVEVA Edge always uses two-digit days and months (such as DD, MM) and four-digit years (such as YYYY), regardless of the order.

To check the date format at any time, simply reference the Date system tag. The value of this tag is always the current system date on the local computer, formatted as a string using the current date format. The "local computer" is the computer where the tag is referenced, regardless of whether it is referenced in a background task on the project runtime server or in screen on a project thin client. The server and each client can have its own date format, because the date format can be changed from the default (see "Changing the date format" below).

The easiest way to reference the Date system tag is to type it into the Watch window, because the value of the tag is immediately displayed there even when your project is not running. You can use the tag anywhere in your project that accepts a tag or expression, however. For more information about system tags, see System Tags Folder.

It is important for you to know what the date format is when you are both developing and running your project, because whenever you specify a date as a string, you must do so in the format that the software expects. If you do not, the software will not be able to parse the string correctly and you will see unexpected behavior during project run time. For example, if the software is currently using the format MM/DD/YYYY and you try pass the date string 2015-02-13 as an argument to a function, the function will return an error code indicating that the specified date is invalid.

Changing the date format

The default date format for all AVEVA Edge software components — the project development environment, the project runtime server, and each project thin client — is MM/DD/YYYY. You cannot change this default. Every time you run the software, it automatically uses this default at least to start.

We can and often do change the default date format for customers in other regions around the world that use different formats, but there are special considerations in doing so, such as maintaining backward compatibility with existing projects and not interfering with future software upgrades. That is why we have not made the default a user-configurable setting. If you need to have your default changed, please contact your software distributor.

You can change the date format at any time after you run a project, however, and the project will keep using the specified format until you either change it again or stop the project. When you stop the project, the date format is reset to the default.

There are a few different ways to change the date format.

First, you can call the function SetDateFormat. This is the most straightforward way, because you can call it anywhere that you normally use the built-in functions. It is most commonly called in a project VBScript Startup Script, to set the date format on the project runtime server, as well as in the VBScript Graphics Script, in the Graphics_OnStart sub-routine, to set the date format on each project thin client. For more information, see SetDateFormat.

Second, if you install Secure Viewer on a computer or device in order to use it as a project thin client, you can specify the date format for that client in Secure Viewer's advanced settings. Doing so should eliminate the need to call the function SetDateFormat on that client, as described above, but it will not override the function if it is called. For more information, see Install the Thin Client software.

Third, when you use the Translation Table to localize your project for other languages or regions, you can also specify the date format as part of the localization. Then, when you set the language during project run time, the date format will be changed with everything else. For more information, see Project Localization.

Please keep in mind that the project runtime server and each project thin client — even the client on the same computer as the server, because it runs in a separate processing thread — can have its own date format, depending on how you design and run your project. This can be useful in some cases, such as when your server is located in one region while your clients are located in another. You might even allow users to change the date format on their clients just to suit their personal preferences. But whatever you do, you must thoroughly test your project to ensure that changing the date format does not cause other issues.