I'm trying to calculate the number of weeks and days that a pet is alive. I'm using SwiftDate for that. So I let the user select a birthdate and compare it to the current date.
I don't want to compare the time... so both the birthdate and current date should have the same time.
My code is:
let greg = Calendar(identifier: .gregorian)
var date1 = birthday // from datepicker
var date2 = Date()
var components1 = greg.dateComponents([.year, .month, .day, .hour, .minute, .second], from: date1)
var components2 = greg.dateComponents([.year, .month, .day, .hour, .minute, .second], from: date2)
components1.hour = 15
components1.minute = 0
components1.second = 0
components2.hour = 15
components2.minute = 0
components2.second = 0
date1 = greg.date(from: components1)!
date2 = greg.date(from: components2)!
let daysAlive = (date2 - date1).in(.day)
let weeksAlive = Int(weeksAlive! / 7)
let restDays = daysAlive! - (weeksAlive * 7)
let aLive = "Age: \(weeksAlive) wk, \(restDays) d (\(daysAlive!) d)"
Output is "Age: 28 wk, 3 d (199 d)"
The code works... but how can I refactor it? And is there an easier way to set the 'same time' for two given dates?
To ignore the time just omit the components for .hour, .minute and .second
let components1 = greg.dateComponents([.year, .month, .day], from: date1)
let components2 = greg.dateComponents([.year, .month, .day], from: date2)
date1 = greg.date(from: components1)!
date2 = greg.date(from: components2)!
This is a simpler solution without any third party library. It calculates the difference once for weekOfMonth and day and once for day with the Calendar method dateComponents(:from:to:. Extra math is not needed.
let greg = Calendar(identifier: .gregorian)
var date1 = greg.date(from: DateComponents(year: 2017, month: 6, day: 25))!
var date2 = Date()
var components1 = greg.dateComponents([.year, .month, .day], from: date1)
var components2 = greg.dateComponents([.year, .month, .day], from: date2)
let weeksAndDays = greg.dateComponents([.weekOfMonth, .day], from: components1, to: components2)
let justDays = greg.dateComponents([.day], from: components1, to: components2)
let aLive = "Age: \(weeksAndDays.weekOfMonth!) wk, \(weeksAndDays.day!) d (\(justDays.day!) d)"
// "Age: 28 wk, 3 d (199 d)"