Date.IntervalFormatStyle
A format style that creates string representations of date intervals.
Declaration
struct IntervalFormatStyleOverview
Use a date interval format style to create user-readable strings in the form of <start> - <end> for your app’s interface, where <start> and <end> are date values that you supply. The format style uses locale and language information, along with custom formatting options, to define the content of the resulting string.
Date.IntervalFormatStyle provides a variety of localized presets and configuration options to create user-visible representations of date intervals. When displaying a date interval to a user, use the formatted(date:time:) instance method of Range<Date>. Set the date and time styles of the date interval format style separately, according to your particular needs.
For example, to create a date interval string with a full date and no time representation, set the Date.IntervalFormatStyle.DateStyle to complete and the Date.IntervalFormatStyle.TimeStyle to omitted. The following example creates a formatted interval string with this style:
if let today = Calendar.current.date(byAdding: .day, value: -120, to: Date()),
let thirtyDaysBeforeToday = Calendar.current.date(byAdding: .day, value: -30, to: today) {
// today: June 5, 2023
// thirtyDaysBeforeToday: May 6, 2023
// Create a Range<Date>.
let last30days = thirtyDaysBeforeToday..<today
let formatted = last30days.formatted(date: .complete, time: .omitted)
// "Saturday, January 30 – Monday, March 1, 2021"
}You can create string representations of date intervals with various levels of brevity using a variety of preset date and time styles. The following example shows date styles of long, abbreviated, and numeric, and time styles of shortened, standard, and complete:
if let today = Calendar.current.date(byAdding: .day, value: -120, to: Date()),
let thirtyDaysBeforeToday = Calendar.current.date(byAdding: .day, value: -30, to: today) {
// today: Mar 1, 2021 at 8:01 PM
// thirtyDaysBeforeToday: Jan 30, 2021 at 8:01 PM
// Create a Range<Date>.
let last30days = thirtyDaysBeforeToday..<today
print(last30days.formatted(date: .long, time: .shortened))
// January 30, 2021, 8:01 PM – March 1, 2021, 8:01 PM
print(last30days.formatted(date: .abbreviated, time: .standard))
// Jan 30, 2021, 8:01:49 PM – Mar 1, 2021, 8:01:49 PM
print(last30days.formatted(date: .numeric, time: .complete))
// 1/30/2021, 8:01:49 PM CST – 3/1/2021, 8:01:49 PM CST
print(last30days.formatted())
// 1/30/21, 8:01 PM – 3/1/21, 8:01 PM
}The default date style is abbreviated and the default time style is shortened.
For full customization of the string representation of a date interval, use the formatted(_:) instance method of Range<Date> and provide a Date.IntervalFormatStyle instance.
You can achieve any customization of date and time representation your app requires by appying a series of convenience modifiers to your format style. The following example applies a series of modifiers to the format style to precisely define the formatting of the year, month, day, hour, minute, and time zone components of the resulting string:
if let today = Calendar.current.date(byAdding: .day, value: -140, to: Date()),
let sevenDaysAfterToday = Calendar.current.date(byAdding: .day, value: 7, to: today) {
// Create a Range<Date>.
let weekFromNow = today..<sevenDaysAfterToday
// Call the .formatted method on a Range<Date> and pass in an instance of Date.IntervalFormatStyle.
weekFromNow.formatted(
Date.IntervalFormatStyle()
.year()
.month(.abbreviated)
.day()
.hour(.defaultDigits(amPM: .narrow))
.weekday(.abbreviated)
) // Wed, Feb 10, 2021, 3 p – Wed, Feb 17, 2021, 3 p
}Date.IntervalFormatStyle provides a convenient factory variable, interval, to shorten the syntax when applying date and time modifiers to customize the format.
if let today = Calendar.current.date(byAdding: .day, value: -140, to: Date()),
let sevenDaysBeforeToday = Calendar.current.date(byAdding: .day, value: -7, to: today) {
// Create a Range<Date>.
let weekBefore = sevenDaysBeforeToday..<today
let localeArray = ["en_US", "sv_SE", "en_GB", "th_TH", "fr_BE"]
for localeID in localeArray {
// Call the .formatted method on a Range<Date> and pass in an instance of Date.IntervalFormatStyle.
print(weekBefore.formatted(.interval
.day()
.month(.wide)
.weekday(.short)
.hour(.conversationalTwoDigits(amPM: .wide))
.locale(Locale(identifier: localeID))))
}
}
// We, February 3, 3 PM – We, February 10, 3 PM
// on 3 februari 15 – on 10 februari 15
// We 3 February, 15 – We 10 February, 15
// พ. 3 กุมภาพันธ์ 15 – พ. 10 กุมภาพันธ์ 15
// me 3 février, 15 h – me 10 février, 15 h