Problem with adding month value to date in Swift - swift

Question

I've got a problem. I'm getting start date of current year with function below:
func startOfYear() -> Date {
var calendar = Calendar(identifier: .iso8601)
let timezone = TimeZone(secondsFromGMT: 0)!
calendar.timeZone = timezone
return calendar.dateComponents([.calendar, .year], from: self).date!
}
My goal is to iterate through this date to extract data for every single month. I use this function to add value to .month to get start date of every month of year:
func getNextMonths(using calendar: Calendar = .iso8601, monthAmount: Int) -> Date {
calendar.date(byAdding: .month, value: monthAmount, to: self.startOfYear())!
}
When I iterate through this fuction and print dates I receive this:
func getMonth() {
for number in 0...12 {
print("month \(number): \(Date().getNextMonths(monthAmount: number))")
}
}
output:
month 0: 2022-01-01 00:00:00 +0000
month 1: 2022-02-01 00:00:00 +0000
month 2: 2022-03-01 00:00:00 +0000
month 3: 2022-03-31 23:00:00 +0000
month 4: 2022-04-30 23:00:00 +0000
month 5: 2022-05-31 23:00:00 +0000
month 6: 2022-06-30 23:00:00 +0000
month 7: 2022-07-31 23:00:00 +0000
month 8: 2022-08-31 23:00:00 +0000
month 9: 2022-09-30 23:00:00 +0000
month 10: 2022-11-01 00:00:00 +0000
month 11: 2022-12-01 00:00:00 +0000
month 12: 2023-01-01 00:00:00 +0000
As you can see there is a problem starting with 2022-03-31 - it supposed to return 2022-04-01 but I don't really know what I'm doing wrong and why I can't achieve this.
EDIT
I've changed fuction getNextMonths to check if it's daylight saving time and it's working now, thanks to [Joakim Danielson][1] for help.
It's silly solution but it works:
func getNextMonths(using calendar: Calendar = .iso8601, monthAmount: Int) -> Date {
if monthAmount == 0 || monthAmount == 1 || monthAmount == 2 || monthAmount == 10 || monthAmount == 11 || monthAmount == 12 {
return calendar.date(byAdding: .month, value: monthAmount, to: self.startOfYear())!
} else {
var dateComponents = DateComponents()
dateComponents.month = monthAmount
dateComponents.hour = 1
return calendar.date(byAdding: dateComponents, to: self.startOfYear())!
}
}

Answer 1

Hey I copied your code as an extension to Date and I got some errors, after some search I finally can run it and it gives me the beginning of each month, here's my changes hope it helps!
extension Date{
func startOfYear() -> Date {
var calendar = Calendar(identifier: .iso8601)
let timezone = TimeZone(secondsFromGMT: 0)!
calendar.timeZone = timezone
return calendar.dateComponents([.calendar, .year], from: self).date!
}
func getNextMonths(using calendar: Calendar, monthAmount: Int) -> Date {
calendar.date(byAdding: .month, value: monthAmount, to: self.startOfYear())!
}
func getMonth() {
for number in 0...12 {
print("month \(number): \(Date().getNextMonths(using: Calendar.current, monthAmount: number))")
}
}
}
Then I made a Date object like this
let d = Date()
print(d.getMonth())
Output (In Indian numbers, but it should be the same)