Why only my last local notification function is getting called?

I'm fairly new to swift and am trying to call multiple functions that request a local notification inside a UISwitch IBAction. I want to send a notification on a certain date - each quarter of the year on months 4, 7, 10, 1. Only the fourth quarter function is getting called. How can I get all four functions to be called? Here is my code:

// UISwitch for quarterly notifications

@IBAction func quarterlyFrequencyTapped(_ sender: UISwitch) {

if quarterlyFrequency.isOn == true {

    firstQuarter(); secondQuarter(); thirdQuarter(); fourthQuarter()

    print("quarterly frequency is \(quarterlyFrequency.isOn)")

} else {

    removeQuarterlyNotification()

    print("quaterly frequency is \(monthlyFrequency.isOn)")

       }

}

// Functions for all four quarters

func firstQuarter() {
    let firstQuarterContent = UNMutableNotificationContent()
    firstQuarterContent.title = "First Quarter"
    firstQuarterContent.subtitle = "Some string"
    firstQuarterContent.body = "Some other string"

    var firstQuarterDate = DateComponents()
    firstQuarterDate.month = 3
    firstQuarterDate.day = 11
    firstQuarterDate.hour = 19
    firstQuarterDate.minute = 20

    let firstQuarterTrigger = UNCalendarNotificationTrigger(dateMatching: firstQuarterDate, repeats: true)
    let firstQuarterRequestIdentifier = "Quarterly"
    let firstQuarterRequest = UNNotificationRequest(identifier: firstQuarterRequestIdentifier, content: firstQuarterContent, trigger: firstQuarterTrigger)
    UNUserNotificationCenter.current().add(firstQuarterRequest, withCompletionHandler: nil)
}

func secondQuarter() {
    let secondQuarterContent = UNMutableNotificationContent()
    secondQuarterContent.title = "Second Quarter"
    secondQuarterContent.subtitle = "Some string"
    secondQuarterContent.body = "Some other string"

    var secondQuarterDate = DateComponents()
    secondQuarterDate.month = 3
    secondQuarterDate.day = 11
    secondQuarterDate.hour = 19
    secondQuarterDate.minute = 21

    let secondQuarterTrigger = UNCalendarNotificationTrigger(dateMatching: secondQuarterDate, repeats: true)
    let secondQuarterRequestIdentifier = "Quarterly"
    let secondQuarterRequest = UNNotificationRequest(identifier: secondQuarterRequestIdentifier, content: secondQuarterContent, trigger: secondQuarterTrigger)
    UNUserNotificationCenter.current().add(secondQuarterRequest, withCompletionHandler: nil)
}

func thirdQuarter() {
    let thirdQuarterContent = UNMutableNotificationContent()
    thirdQuarterContent.title = "Third Quarter"
    thirdQuarterContent.subtitle = "Some string"
    thirdQuarterContent.body = "Some other string"

    var thirdQuarterDate = DateComponents()
    thirdQuarterDate.month = 3
    thirdQuarterDate.day = 11
    thirdQuarterDate.hour = 19
    thirdQuarterDate.minute = 22

    let thirdQuarterTrigger = UNCalendarNotificationTrigger(dateMatching: thirdQuarterDate, repeats: true)
    let thirdQuarterRequestIdentifier = "Quarterly"
    let thirdQuarterRequest = UNNotificationRequest(identifier: thirdQuarterRequestIdentifier, content: thirdQuarterContent, trigger: thirdQuarterTrigger)
    UNUserNotificationCenter.current().add(thirdQuarterRequest, withCompletionHandler: nil)
}

func fourthQuarter() {
    let fourthQuarterContent = UNMutableNotificationContent()
    fourthQuarterContent.title = "Fourth Quarter"
    fourthQuarterContent.subtitle = "Some string"
    fourthQuarterContent.body = "Some other string"

    var fourthQuarterDate = DateComponents()
    fourthQuarterDate.month = 3
    fourthQuarterDate.day = 11
    fourthQuarterDate.hour = 19
    fourthQuarterDate.minute = 23

    let fourthQuarterTrigger = UNCalendarNotificationTrigger(dateMatching: fourthQuarterDate, repeats: true)
    //let trigger = UNTimeIntervalNotificationTrigger(timeInterval: 60, repeats: true)
    let fourthQuarterRequestIdentifier = "Quarterly"
    let fourthQuarterRequest = UNNotificationRequest(identifier: fourthQuarterRequestIdentifier, content: fourthQuarterContent, trigger: fourthQuarterTrigger)
    UNUserNotificationCenter.current().add(fourthQuarterRequest, withCompletionHandler: nil)
}

I think you're on +iOS10 and you're using UserNotifications framework right?

Very likely your identifiers have the same and each are UPDATING the previous notification.

The reason identifier exists is to assist you with updated a previous notification that has the same identifier. For example you send a notification to update the score from 0-0 to 0-1. And instead of having 2 notifications on the screen you now have only one.

Your fix is to use different identifiers for each.

For more see this moment for the WWDC video

UPDATE after your edit: just as I said...all your notifications have "Quarterly" as their identifier. Give them each a separate name.