init(to:allowedFields:maxFieldCount:sign:)

Create a format style to display the offset to a certain date.

Declaration

init(to anchor: Date, allowedFields: Set<Date.ComponentsFormatStyle.Field> = [.year, .month, .week, .day, .hour, .minute, .second], maxFieldCount: Int = 2, sign: NumberFormatStyleConfiguration.SignDisplayStrategy = .automatic)

Parameters

anchor:
The date the offset is measured to from the format input.
allowedFields:
The units of time that may be used in the format to express the offset.
maxFieldCount:
The number of fields that can be shown at once. For example, 1 hour, 34 minutes, and 23 seconds is shown as 1 hour, 34 minutes by default, but as 1 hour if the maxFieldCount is set to one.
sign:
The strategy for displaying a sign to signal whether the offset points to ward the future or past.

Discussion

The time format (3:46) is used as long as only minutes and seconds, or hours, minutes, and second may be shown. Otherwise, calendar units are used, resulting in outputs like 3 months, 11 days.

The offset to the anchor is “positive” if the formatted date is greater than the given anchor specified here. Conversely, “negative” offsets are displayed if the input date is smaller than the anchor.