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content / browser / date_time_chooser / ios / date_time_chooser_util.mm [blame]
// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#import "content/browser/date_time_chooser/ios/date_time_chooser_util.h"
NSDate* GetDateFromNumberOfMonths(NSInteger month) {
NSDateComponents* components = [[NSDateComponents alloc] init];
// https://html.spec.whatwg.org/multipage/input.html#month-state-(type=month)
// The integer of string value is the number of months between 1970 and the
// parsed month.
components.year = month / 12 + 1970;
// Month is started from 1 for January.
components.month = (month % 12) + 1;
components.day = 1;
// https://html.spec.whatwg.org/multipage/input.html#date-state-(type=date)
// The spec says that user agents are not required to support converting dates
// and times from earlier periods to the Gregorian calendar.
NSCalendar* calendar = [[NSCalendar alloc]
initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
calendar.timeZone = [NSTimeZone timeZoneWithAbbreviation:@"UTC"];
return [calendar dateFromComponents:components];
}
NSInteger GetNumberOfMonthsFromDate(NSDate* date) {
unsigned unitFlags = NSCalendarUnitYear | NSCalendarUnitMonth;
NSCalendar* calendar = [[NSCalendar alloc]
initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
calendar.timeZone = [NSTimeZone timeZoneWithAbbreviation:@"UTC"];
NSDateComponents* components = [calendar components:unitFlags fromDate:date];
// Month is started from 1 for January.
return (components.year - 1970) * 12 + (components.month - 1);
}