This should be a really simple question but I just can't seem to wrap my head around it.
Given my timezone is EDT (GMT-4), why does 04:00 in GMT turn into 23:00 and not 00:00?
// The offset is -4 hours
let offsetFromGMT = Calendar.current.timeZone.secondsFromGMT() / 60 / 60
// 2017-03-12 04:00
var destinationComponents = DateComponents()
destinationComponents.timeZone = TimeZone(secondsFromGMT: 0)
destinationComponents.year = 2017
destinationComponents.month = 03
destinationComponents.day = 12
destinationComponents.hour = -offsetFromGMT // 4 hours
// Why is this 2017-03-11 23:00 and not 2017-03-12 00:00?
let date = Calendar.current.date(from: destinationComponents)!
// Outputs 23
Calendar.current.dateComponents([.hour], from: date).hour
Calendar.current.timeZone.secondsFromGMT()
is the current GMT offset for your time zone. In your case that
is 4 hours, because the current time zone in New York is EDT = GMT-4,
with daylight saving time active.
So your destinationComponents and date are four o'clock in
the morning Greenwich time:
2017-03-12 04:00:00 +0000
At that point, the time zone in New York was EST = GMT-5, and
daylight saving time not active. Therefore that date is 2017-03-11 23:00 in your local time zone.
I would proceed differently, avoiding "secondsFromGMT".
Example: "2017-03-12 00:00:00" New York time is "2017-03-12 05:00:00" GMT.
var srcComponents = DateComponents()
srcComponents.timeZone = TimeZone(identifier: "America/New_York")!
srcComponents.year = 2017
srcComponents.month = 3
srcComponents.day = 12
srcComponents.hour = 0
srcComponents.minute = 0
let date = Calendar.current.date(from: srcComponents)!
print(date) // 2017-03-12 05:00:00 +0000
Related
I have time and time zone, what I need is I just want to convert like this Wed, 11 Dec 2019 19:00:00 +0530 and then I need to convert like this 1576071000.
So for I tried like this
time = "19"
hour = "00"
time_zone = "IST"
e = DateTime.now.change({hour: time, minute: hour})
I get the exact output, but I need to convert with timezone. that means something like this
DateTime.now.change({hour: time, minute: hour}).time_zone('IST')
credit to #engineersmnky
hour = 19
minute = 0
time_zone = 'Chennai'
e = Time.zone.now.change({hour: hour, minute: minute}).in_time_zone(time_zone).to_i
You need to convert it to UTC:
DateTime.now.change({hour: time, minute: hour}).time_zone('IST').utc
Or if you are in Rails 4 or above you can use in_time_zone:
DateTime.now.change({hour: time, minute: hour}).in_time_zone('IST').utc
I need to compare two times in Swift and using NSComparisonResult I could get correct result until it comes to time between 10 PM - 11:59 PM. It shows opposite result for these times. Anyone know what's the issue with this? Below is sample code and scenario's. 10:30:00 PM is example time to test, but you can test it with any time.
// For test, Current time 10:30:00 PM
let currentTime = NSDateFormatter.localizedStringFromDate(NSDate(), dateStyle: .NoStyle, timeStyle: .LongStyle)
let closeTimeCompareResult: NSComparisonResult = currentTime.compare("10:00:00 PM EDT")
print("DinnerClose: \(closeTimeCompareResult.rawValue)")
// Expected result is -1 but, getting as 1
// It works perfect until 9:59:59 PM
let closeTimeCompareResult9: NSComparisonResult = currentTime.compare("9:00:00 PM EDT")
print("DinnerClose: \(closeTimeCompareResult9.rawValue)")
// As expected result is -1
You're performing a string comparison. So you're comparing these two strings, for example:
10:00:00 PM EDT
9:00:00 PM EDT
A string comparison compares the corresponding characters of each string, starting with the first character of each. The first character of "10:00:00 PM EDT" is "1" and the first character of "9:00:00 PM EDT" is "9". In Unicode and ASCII, "9" is code point 57 and "1" is code point 49. Since 57 > 49, "9" > "1", and "9:00:00 PM EDT" > "10:00:00 PM EDT".
You probably want to extract the hour, minute, and second from the input date, and then compare them numerically. If you've upgraded to Xcode 7.3 with Swift 2.2, then you can use a tuple comparison like this:
let date = NSDate()
let components = NSCalendar.currentCalendar().components([.Hour, .Minute, .Second], fromDate: date)
let hms = (components.hour, components.minute, components.second)
if hms >= (21, 0, 0) && hms < (22, 30, 0) {
print("\(date) is between 9 PM and 10:30 PM in the system's time zone.")
}
I am current at timezone UTC-05:00. When I call the function NSDate(timeIntervalSince1970:0), it returns back "Dec 31, 1969, 7:00 PM"
let date = NSDate.init(timeIntervalSince1970: 0) // "Dec 31, 1969, 7:00 PM"
print(date) // "1970-01-01 00:00:00 +0000\n"
I read about this How to get NSDate day, month and year in integer format? But the problem is that with the following, I always get 1969-12-31 because of the 5 hour time difference.
let calendar = NSCalendar.currentCalendar()
calendar.getEra(&era, year:&year, month:&month, day:&day, fromDate: date)
year // 1969
month // 12
day // 31
var hour = 0, minute = 0, second = 0
calendar.getHour(&hour, minute: &minute, second: &second, nanosecond: nil, fromDate: date)
hour // 19
minute // 0
second // 0
Is there a way to get the current year, month, day values and etc. in the current timezone. What I am looking for here is:
year // 1970
month // 01
day // 01
The timeIntervalSince1970 initializer gives you (as documented) an NSDate which is some number of seconds since Jan 1 1970 at 00:00:00 in UTC, not in your local time zone. Those results you're getting are correct, because they're showing your local time zone's offset from that time. You're passing in 0, so you're getting Jan 1 1970 at 00:00:00 UTC, and then NSCalendar is giving you the equivalent date and time in your local time zone.
If you want to get Jan 1 1970 at 00:00:00 in your local time zone, you need to request that date specifically from NSCalendar:
let calendar = NSCalendar.currentCalendar()
calendar.timeZone = NSTimeZone.localTimeZone()
let date = calendar.dateWithEra(1, year: 1970, month: 1, day: 1, hour: 0, minute: 0, second: 0, nanosecond: 0)
calendar.getEra(&era, year:&year, month:&month, day:&day, fromDate: date!)
year // 1970
month // 1
day // 1
This is not a 0 offset for timeIntervalSince1970. If you check, you'll see that the result corresponds to your time zone's offset from UTC:
date?.timeIntervalSince1970 // 25200, for me
This will return the current date ex. 02/26/2016
// Format date so we may read it normally
let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "dd/M/yyyy"
let currentDate = String(dateFormatter.stringFromDate(NSDate()))
Swift 3.0
NSDateFormatter > DateFormatter && NSDate > Date
let df = DateFormatter()
df.timeZone = .current
df.dateStyle = .medium
df.timeStyle = .short
df.dateFormat = "dd/M/yyyy"
let currentDate = df.string(from: Date())
I want to set a constraint on a Parse query, that takes a birthday ( date), and only gathers results which are within 10 years.
So if the date is something like (1954-01-10 07:00:00 +0000)
then I want to get all records from 1944 to 1964.
Is there some way to do this using Parse query code?
Or,
do I have to obtain the date, then use swift code to offset it by 10 years, then write something like this
let currentUserBirthday = PFUser.currentUser()?.objectForKey("birthday")!
// set date 10 years greater and lower than currentUserBirthday
let datePlus10 = // add 10 years to date
let dateMinus10 = // subtract 10 years from date
dailyFourQuery?.whereKey("birthday", greaterThanOrEqualTo: datePlus10)
dailyFourQuery?.whereKey("birthday", lessThanOrEqualTo: dateMinus10)
edit: hey guys, i solved this by getting the age from the date, then adding or subtracting the integer offset from that number,
then using NSCalendar and creating components with modified values.
Thanks for all the help.
let currentUserBirthdayNSDate = currentUserBirthday as! NSDate
let dateComponents = calendar.components([NSCalendarUnit.Day, NSCalendarUnit.Month, NSCalendarUnit.Year, NSCalendarUnit.WeekOfYear, NSCalendarUnit.Hour, NSCalendarUnit.Minute, NSCalendarUnit.Second, NSCalendarUnit.Nanosecond], fromDate: currentUserBirthdayNSDate)
let componentsPlus10 = NSDateComponents()
componentsPlus10.day = dateComponents.day
componentsPlus10.month = dateComponents.month
componentsPlus10.year = dateComponents.year + 10
componentsPlus10.hour = dateComponents.hour
componentsPlus10.minute = dateComponents.minute
You can refer to SwiftDate
// Reference date is: Thu, 19 Nov 2015 19:00:00 UTC (1447959600 from 1970)
let refDate = NSDate(timeIntervalSince1970: 1447959600)
// Remember: all parameters are optional; in this example we have ignored minutes and seconds
let newDate = refDate.add(years: 1, months: 2, days: 1, hours: 2)
// newdate is 2017-01-21 14:00:00 +0000
// This is equivalent to
let newDate2 = refDate + 1.years + 2.months + 1.days + 2.hours
do you want this?
I need to show time elapsed. I have the dates in following format.
Date1 = Thu May 23 10:10:10 EDT 2013
Date2 = Tue May 21 10:10:10 EDT 2013
I currently did TimeDuration duration=TimeCategory.minus(now,LaunchTime)
And my output shows something like 2 days, 23 minutes, 25.154 seconds
What I want to show instead of 2 days, 23 minutes, 25.154 seconds is something like 48:23:25(in hours and minutes).
You can do something like this to create a new TimeDuration with the days turned into hours:
import groovy.time.TimeDuration
import groovy.time.TimeCategory
date1 = Date.parseToStringDate( 'Thu May 23 10:10:10 EDT 2013' )
date2 = Date.parseToStringDate( 'Tue May 21 12:14:10 EDT 2013' )
// Normalize method to return a new TimeDuration
TimeDuration normalize( TimeDuration tc ) {
new TimeDuration( ( tc.days != 0 ? tc.days * 24 : 0 ) + tc.hours,
tc.minutes, tc.seconds, tc.millis )
}
// Then use the category to subtract the dates, and call normalize
TimeDuration normalized = use( groovy.time.TimeCategory ) {
normalize( date1 - date2 )
}
println normalized