How to get 1 hour ago from a date in iOS swift?
Please read the NSDate
class reference.
let oneHourAgo = NSDate.dateWithTimeIntervalSinceNow(-3600)
should do it.
Or, for any NSDate
object:
let oneHourBack = myDate.dateByAddingTimeInterval(-3600)
Swift 4:
let oneHourAgo = NSDate(timeIntervalSinceNow: -3600)
Use this method and paste in your helper class.
Updated for Swift 3 and Xcode 8.3
class func timeAgoSinceDate(_ date:Date,currentDate:Date, numericDates:Bool) -> String {
let calendar = Calendar.current
let now = currentDate
let earliest = (now as NSDate).earlierDate(date)
let latest = (earliest == now) ? date : now
let components:DateComponents = (calendar as NSCalendar).components([NSCalendar.Unit.minute , NSCalendar.Unit.hour , NSCalendar.Unit.day , NSCalendar.Unit.weekOfYear , NSCalendar.Unit.month , NSCalendar.Unit.year , NSCalendar.Unit.second], from: earliest, to: latest, options: NSCalendar.Options())
if (components.year! >= 2) {
return "\(components.year!) years ago"
} else if (components.year! >= 1){
if (numericDates){
return "1 year ago"
} else {
return "Last year"
}
} else if (components.month! >= 2) {
return "\(components.month!) months ago"
} else if (components.month! >= 1){
if (numericDates){
return "1 month ago"
} else {
return "Last month"
}
} else if (components.weekOfYear! >= 2) {
return "\(components.weekOfYear!) weeks ago"
} else if (components.weekOfYear! >= 1){
if (numericDates){
return "1 week ago"
} else {
return "Last week"
}
} else if (components.day! >= 2) {
return "\(components.day!) days ago"
} else if (components.day! >= 1){
if (numericDates){
return "1 day ago"
} else {
return "Yesterday"
}
} else if (components.hour! >= 2) {
return "\(components.hour!) hours ago"
} else if (components.hour! >= 1){
if (numericDates){
return "1 hour ago"
} else {
return "An hour ago"
}
} else if (components.minute! >= 2) {
return "\(components.minute!) minutes ago"
} else if (components.minute! >= 1){
if (numericDates){
return "1 minute ago"
} else {
return "A minute ago"
}
} else if (components.second! >= 3) {
return "\(components.second!) seconds ago"
} else {
return "Just now"
}
}
Use of this method:
var timeAgo:String=AppHelper.timeAgoSinceDate(date, numericDates: true)
Print("\(timeAgo)") // Ex- 1 hour ago
For correct calculations involving NSDate that take into account all edge cases of different calendars (e.g. switching between day saving time) you should use NSCalendar class:
Swift 3+
let earlyDate = Calendar.current.date(
byAdding: .hour,
value: -1,
to: Date())
Older
// Get the date that was 1hr before now
let earlyDate = NSCalendar.currentCalendar().dateByAddingUnit(
.Hour,
value: -1,
toDate: NSDate(),
options: [])
According to your needs, you may choose one of the 3 following Swift 5 methods to get one hour ago from a Date
instance.
1. date(byAdding:value:to:wrappingComponents:)
Calendar
has a method called date(byAdding:value:to:wrappingComponents:)
. date(byAdding:value:to:wrappingComponents:)
has the following declaration:
func date(byAdding component: Calendar.Component, value: Int, to date: Date, wrappingComponents: Bool = default) -> Date?
Returns a new
Date
representing the date calculated by adding an amount of a specific component to a given date.
The Playground code below shows how to use it:
import Foundation
let now = Date()
let oneHourAgo = Calendar.current.date(byAdding: .hour, value: -1, to: now)
print(now) // 2016-12-19 21:52:04 +0000
print(String(describing: oneHourAgo)) // Optional(2016-12-19 20:52:04 +0000)
2. date(byAdding:to:wrappingComponents:)
Calendar
has a method called date(byAdding:to:wrappingComponents:)
. date(byAdding:value:to:wrappingComponents:)
has the following declaration:
func date(byAdding components: DateComponents, to date: Date, wrappingComponents: Bool = default) -> Date?
Returns a new
Date
representing the date calculated by adding components to a given date.
The Playground code below shows how to use it:
import Foundation
let now = Date()
var components = DateComponents()
components.hour = -1
let oneHourAgo = Calendar.current.date(byAdding: components, to: now)
print(now) // 2016-12-19 21:52:04 +0000
print(String(describing: oneHourAgo)) // Optional(2016-12-19 20:52:04 +0000)
Alternative:
import Foundation
// Get the date that was 1hr before now
let now = Date()
let components = DateComponents(hour: -1)
let oneHourAgo = Calendar.current.date(byAdding: components, to: now)
print(now) // 2016-12-19 21:52:04 +0000
print(String(describing: oneHourAgo)) // Optional(2016-12-19 20:52:04 +0000)
3. addingTimeInterval(_:)
(use with caution)
Date
has a method called addingTimeInterval(_:)
. addingTimeInterval(_:)
has the following declaration:
func addingTimeInterval(_ timeInterval: TimeInterval) -> Date
Return a new
Date
by adding aTimeInterval
to thisDate
.
Note that this method comes with a warning:
This only adjusts an absolute value. If you wish to add calendrical concepts like hours, days, months then you must use a
Calendar
. That will take into account complexities like daylight saving time, months with different numbers of days, and more.
The Playground code below shows how to use it:
import Foundation
let now = Date()
let oneHourAgo = now.addingTimeInterval(-3600)
print(now) // 2016-12-19 21:52:04 +0000
print(oneHourAgo) // 2016-12-19 20:52:04 +0000