With Windows 10 version 1703, Microsoft introduced built-in ICU support, allowing applications to use the system provided ICU instead of bundling their own. By leveraging this, Xojo now benefits from automatic updates, a reduced app footprint, and improved compatibility with the latest Unicode and locale data.

Which parts of the framework use ICU?

One of the main areas where ICU is used is the DateTime class, which includes Locale and TimeZone support. This helps with formatting dates and times and handling timezone differences reliably. ICU is also used for number formatting and string manipulation, particularly when working with characters like emojis and other complex Unicode symbols.

What benefits can be observed?

• Fewer DLLs
• 45MB smaller app sizes
• Faster execution times, i.e. DateTime.Now is roughly 10% faster
• Daylight saving time no longer requires a rebuild of your Xojo app

What are the new requirements?

As mentioned, Windows began including prebuilt ICU libraries starting with Windows 10 version 1703, so your apps won’t run on earlier versions. However, if you’re using Windows Server 2019, you’ll need to be on at least version 1809.

Conclusion

By shifting to Windows’ built-in ICU libraries, Xojo has eliminated the need for manual ICU updates and reducing app file sizes. This change means your apps will always have the latest updates for date/time, locale, and character handling, thanks to Windows updates.

William Yu grew up in Canada learning to program BASIC on a Vic-20. He is Xojo’s resident Windows and Linux engineer, among his many other skills. Some may say he has joined the dark side here in the USA, but he will always be a Canadian at heart.

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Compact Display Style

When using the Compact Display Style, the control adjusts itself to offer two fields for Date and Time selection or just one field in those cases when the Display Mode is set to Date or Time. In any case, this Display Style consumes less real screen space in the UI, making it ideal for more compact interface designs.

For example, use it when designing custom cells for a MobileTable DataSource:

Inline Display Style

On the other hand, the Inline Display Style is ideal for date selection because it renders a calendar in the view that speeds up the date selection by the user. It includes options for rapidly moving among the month or the year to be displayed. This is much faster compared with spinning the wheel for a date in the Wheels Display Style:

Conclusion

We are sure that the new Inline and Compact Display Styles will help polish your UIs and we look forward to seeing how you use them in your iOS apps. Thank you to everyone who filed cases and offered feedback for this release.

Happy coding!

Javier Menendez is an engineer at Xojo and has been using Xojo since 1998. He lives in Castellón, Spain and hosts regular Xojo hangouts en español. Ask Javier questions on Twitter at @XojoES or on the Xojo Forum.

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You can now offer your users the ability to select a date and/or time value in a graphical way (from a Calendar view, for example) or using the text mode the user can enter the values for the year, month, day, hour, minute and (optionally) also the seconds. Of course you will be able to display a preselected date and/or time on the control.

In order to start using the DateTimePicker control in your apps: Drag and drop the DateTimePicker control from the Library to the Window Layout. Use the Inspector Panel to set the instance in graphic or text mode (on Linux you are limited graphic mode).

Implement the DateChanged Event Handler in the DateTimePicker control instance. You’ll receive as parameter a DateTime object with the selected date and time values.

Optionally you can set other properties via code, for example: display the seconds value for the Time section of the DateTimePicker, set the initial date/time values or set a minimum and/or maximum selectable date value for the Calendar section.

All the properties are settable via code at runtime; so this means that you can change the behavior of the DateTimePicker as you need.

Questions? Ask me about Xojo programming on Twitter @XojoES or on the Xojo Forum.

DateTime is cool. You can create a variable that stores the date/time now with:

Var dt As DateTime = DateTime.Now

Or:

Var dt As New DateTime(TimeZone.Current)

The second variant allows you to simply find the date/time now in any time zone:

Var dt As New DateTime(New TimeZone("NZ")) ' Local time for me and Rocket Lab launch site 1

Or:

Var dt As New DateTime(New TimeZone("UTC")) ' Local time in Greenwich

Sometimes you need to calculate a date:

Var dt As DateTime = DateTime.Now.AddInterval(0, 1) ' today next month

Or:

Var dt As DateTime = DateTime.Now.SubtractInterval(0, 1) ' today last month

You can obviously use the components of a DateTime in your calculation, e.g. finding the 20^th of next month:

Var dt As DateTime = DateTime.Now.AddInterval(0, 1, 20 – DateTime.Now.Day)

DateTime is based on seconds from 1970 which allows for simple conversions between TimeZones and is daylight savings time aware.

How awesome is this?

Wayne Golding has been a Xojo developer since 2005. He operates the IT Company Axis Direct Ltd www.axisdirect.nz which primarily develops applications using Xojo that integrate with Xero www.xero.com. Wayne’s hobby is robotics where he uses Xojo to build applications for his Raspberry Pi, often implementing IoT for remote control.

Date

• Mutable (you can change any of its properties without having to create a new Date)

On the surface this sounds great, but you can get into some ambiguous Dates depending on the order of operation, for example:

Dim d As New Date(2019, 2, 28)    // February 28, 2019
d.Day = 31   // February 31, 2019?
d.Month = 3

In reality since February 31 is not a valid date we have to coerce it into one, in this case we roll over as 3 days into March, so after the Day has been set to 31 the actual date is now March 3, 2019, probably not what the user intended.

• Uses local TimeZone (no way to use a different TimeZone)

Consider living in California and trying to determine the time in New York. With the Date class you’d have to calculate the time offset yourself.

• Uses current locale for date string formatting (no way to use a different locale)

If you’re trying to display something for your French or Spanish speaking compadre and you’re on a English speaking region, you’d have to format the date yourself.

• Fixed GMTOffset (no understanding of daylight savings rollover)

The GMTOffset is always the current TimeZone offset, unless its has been specifically set in one of the Date constructors.

DateTime

• Immutable (none of its properties can be modified, you’d have to create a new DateTime)

While this may seem more restrictive, this provides protection against setting ambiguous dates. You can use DateInterval and/or DateTime.AddInterval to manipulate the date which is returned as a new DateTime object.

• TimeZone savvy

Each DateTime object can be associated with a different TimeZone. For a list of all the supported TimeZone names, see:
https://docs.oracle.com/cd/E41183_01/DR/ICU_Time_Zones.html

• Date formats are locale savvy

Instead of being tied to presenting a date string in the current locale, you can specify a different locale in which to display your formatted date string.

• Daylight savings aware

A TimeZone is always associated with a DateTime object (if none is specified then the current TimeZone is used), you can use the TimeZone.SecondsFromGMTOffset to determine if the Date is in daylight savings.

Daylight savings boundary behavior

When daylight savings end on November 3, 2019 at 2:00am the date will fall back one hour so we really are on November 3, 2019 at 1:00am. So how does Xojo handle the case where a user sets the date to be November 3, 2019 at 1:00am? Is it just before daylight savings or after? The answer is, after, with the TimeZone GMTOffset adjusted accordingly.

For more information about the new DateTime class, make sure to check out the documentation page on it: http://documentation.xojo.com/api/deprecated/date.htmlTime