Setting access date in UserDefaults to run a function once a day

Hello there,

Beginner here - I have a function that gives a "word of the day", but I want it to stay in the device for a full 24 hours (regardless of how many times the app is opened or closed) and then rerun the function again the next day to give a new word.

In order to do this I am trying to user UserDefaults, to save the date and to only run the code when it is a new day. I struggling a lot since all the tutorials online are about using UserDefaults to store user preferences.

This is my terrible code so far which makes no sense...

Code Block 
 override func viewDidLoad() {
    super.viewDidLoad()

    //save date?

Code Block 
 UserDefaults.standard.set(Date(), forKey: "lastAccessDate")
     
let lastAccessDate = UserDefaults.standard.object(forKey: "lastAccessDate") as? Date ?? Date()
     

//if it is same day show me the content picked from "selectedVocab://

Code Block 
    if Calendar.current.isDateInToday(lastAccessDate){ 
    userDefaults.value(forKey: "selectedVocab") =
     

//if not the same day rerun code

Code Block 
  if !Calendar.current.isDateInToday(lastAccessDate) {
      updateWordOfTheDay()
    }
    }
}

//my function

Code Block 
 func updateWordOfTheDay() {
    let selectedVocab = retrieveVocab() // which returns on set of shuffled data
    updateLabels(using: selectedVocab)
    sendNotification(using: selectedVocab) 
    //saves to userdefaults?
    userDefaults.setValue(selectedVocab, forKey: "selectedVocab")