Converting date string with timezone to seconds in swift

Question

I have a date string: "13 December 2017"

a time zone string: "Asia/Kolkata"

What is the way to get Epoch timestamp in seconds in Swift 4.0?

If you have simplistic string as "13 December 2017" to convert to date, what is the place for timezone? — Hexfire, Dec 11 '17 at 07:47
@Hexfire I need to generate epoch timestamp for that date string in that time zone irrespective of device's local timezone and send it to the server. — Ashok, Dec 11 '17 at 07:55

score 3 · Accepted Answer · edited Dec 11 '17 at 11:20

here the solution:

// your input
let dateStr = "13 December 2017"
let timeZoneStr = "Asia/Kolkata"

// building the formatter
let formatter = DateFormatter()
formatter.dateFormat = "d MMMM yyyy"
formatter.timeZone = TimeZone(identifier: timeZoneStr)

// extracting the epoch
let date = formatter.date(from: dateStr) // Dec 13, 2017 at 3:30 AM
let epoch = date?.timeIntervalSince1970
print(epoch ?? "") // 1513103400

for information, this link: http://userguide.icu-project.org/formatparse/datetime is an interesting source of date formatters

Updated:

Using Extension:

extension String {

  func epoch(dateFormat: String = "d MMMM yyyy", timeZone: String? = nil) -> TimeInterval? {
    // building the formatter
    let formatter = DateFormatter()
    formatter.dateFormat = dateFormat
    if let timeZone = timeZone { formatter.timeZone = TimeZone(identifier: timeZone) }

    // extracting the epoch
    let date = formatter.date(from: self)
    return date?.timeIntervalSince1970
  }

}

"13 December 2017".epoch(timeZone: "Asia/Kolkata") // 1513103400

Tx. Updated with an extension :) – Ashok Dec 11 '17 at 11:20 — Ashok, Dec 11 '17 at 11:20

Converting date string with timezone to seconds in swift

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