NSDate.beginningOfHour is not compatible with Daylight Saving Time. #31
Comments
|
@norio-nomura Thank you for reporting! Do you mean that a NSDate object which has own time zone is not compatible with daylight-saving time? |
Sorry, above is not correct. I don't know about Timepiece's NSDate extension for supporting timezone. //: Playground - noun: a place where people can play
import Foundation
import Timepiece
extension NSCalendar {
public func startOfHourForDate(date: NSDate) -> NSDate {
let comp = components(.CalendarUnitMinute | .CalendarUnitSecond | .CalendarUnitNanosecond, fromDate: date)
comp.minute *= -1
comp.second *= -1
comp.nanosecond *= -1
return dateByAddingComponents(comp, toDate: date, options: .MatchNextTime)!
}
}
let timeZone = NSTimeZone(name: "Australia/Adelaide")!
timeZone.daylightSavingTime // true
NSTimeZone.setDefaultTimeZone(timeZone)
let calendar = NSCalendar.currentCalendar()
let formatter = NSDateFormatter()
formatter.dateFormat = "yyyy-MM-dd HH:mm:ss Z"
formatter.locale = NSLocale(localeIdentifier: "en_US_POSIX")
// This Year
let comp = calendar.components(.CalendarUnitEra | .CalendarUnitYear, fromDate: NSDate())
let startOfThisYear = calendar.dateFromComponents(comp)!
var prevDate = startOfThisYear
// transition
while let transition = timeZone.nextDaylightSavingTimeTransitionAfterDate(prevDate)
where calendar.isDate(transition, equalToDate: startOfThisYear, toUnitGranularity: .CalendarUnitYear) {
println("transition: \(formatter.stringFromDate(transition))(\(transition))")
let twoHourBefore = transition - 2.hours
let twoHourAfter = transition + 2.hours
var time = twoHourBefore
while time <= twoHourAfter {
let beginningOfHour = calendar.startOfHourForDate(time)
// check equality by hour
if calendar.isDate(time, equalToDate: beginningOfHour, toUnitGranularity: .CalendarUnitHour) {
println("\(formatter.stringFromDate(time))(\(time)) is in \(formatter.stringFromDate(beginningOfHour))(\(beginningOfHour))")
} else {
println("\(formatter.stringFromDate(time))(\(time)) is not in \(formatter.stringFromDate(beginningOfHour))(\(beginningOfHour))")
}
time = time + 5.minutes
}
prevDate = transition
} |
|
@norio-nomura What problem does your code demonstrate? |
|
Sorry, my code is too complex for describing issue. //: Playground - noun: a place where people can play
import Foundation
import Timepiece
let timeZone = NSTimeZone(name: "Australia/Adelaide")!
timeZone.daylightSavingTime // true
NSTimeZone.setDefaultTimeZone(timeZone)
let calendar = NSCalendar.currentCalendar()
let transitionDay = calendar.dateWithEra(1, year: 2015, month: 4, day: 5, hour: 0, minute: 0, second: 0, nanosecond: 0)!
let formatter = NSDateFormatter()
formatter.dateFormat = "yyyy-MM-dd HH:mm:ss Z"
var stepBy1Hour = transitionDay
println("step by 1 hour | beginningOfHour | NG?")
println("-------------- | --------------- | ---")
while calendar.isDate(stepBy1Hour, equalToDate: transitionDay, toUnitGranularity: .CalendarUnitDay) {
let beginningOfHour = stepBy1Hour.beginningOfHour
print("\(formatter.stringFromDate(stepBy1Hour))|\(formatter.stringFromDate(beginningOfHour))")
if calendar.isDate(stepBy1Hour, equalToDate: beginningOfHour, toUnitGranularity: .CalendarUnitHour) {
println("|")
} else {
println("|<- NG")
}
stepBy1Hour = stepBy1Hour + 1.hour
}
|
|
@norio-nomura Thanks! I will try to write tests and fix the problem. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Sample code is following:
result is following:
On above result, "2015-04-05 02:00:00" appear twice on +1030 and +0930 before transition.
beginningOfHourshould return +1030 value when receiver was +1030The text was updated successfully, but these errors were encountered: