Swift 3 Easy way to truncate Date to start of the day/month/year
Calendar
has dedicated methods:
Start of the day
let truncated = Calendar.current.startOfDay(for: Date())
Start of the month
let now = Date() var startOfMonth = now var timeInterval : TimeInterval = 0.0 Calendar.current.dateInterval(of: .month, start: &startOfMonth, interval: &timeInterval, for: now) print(startOfMonth)
Start of the year
let now = Date() var startOfYear = now var timeInterval : TimeInterval = 0.0 Calendar.current.dateInterval(of: .year, start: &startOfYear, interval: &timeInterval, for: now) print(startOfYear)
Or as Date
extension
extension Date {
func startOf(_ dateComponent : Calendar.Component) -> Date {
var calendar = Calendar.current
calendar.timeZone = TimeZone(secondsFromGMT: 0)!
var startOfComponent = self
var timeInterval : TimeInterval = 0.0
calendar.dateInterval(of: dateComponent, start: &startOfComponent, interval: &timeInterval, for: now)
return startOfComponent
}
}
let now = Date()
let startOfDay = now.startOf(.day)
let startOfMonth = now.startOf(.month)
let startOfYear = now.startOf(.year)
Regarding the time zone issue you can set the time zone of the current calendar accordingly.
Note the +0000
at the end of the time in your sample.
The start of the day where? I updated the sample to show what you want.
var comp: DateComponents = Calendar.current.dateComponents([.year, .month, .day], from: Date())
comp.timeZone = TimeZone(abbreviation: "UTC")!
let truncated = Calendar.current.date(from: comp)!
print(truncated)
It prints 2017-06-14 00:00:00 +0000
. Again, note the +0000 at the end.
By default the timezone is set to be the current timezone and the hour, minute, and second are 0 in that timezone.
I will assume that you want the current timezone. With that stipulation, your code is correct.