LocalDate to string format with HH:mm

I have a Kotlin code that retrives date (in text field) from SQLite DB and put it into a LocalDate variable (pill.startDay) from whom I show the date as below

val dtf: DateTimeFormatter = DateTimeFormatter.ofPattern("dd/MM/uuuu", Locale.ITALY)
val startDayStr: String =dtf.format(pill.startDay)
holder.tvStartDate.text = "Start: $startDayStr"

Now I need to show also hours and minutes but I've tryed many patterns (like "dd/MM/uuuu HH:mm" or "dd/MM/uuuu'T'HH:mm" or "dd/MM/uuuu HH:mm z") without success (the app always crashes)

The full data class is:

data class Pill(val id: Int,
                val pillName: String,
                val yesDays: Int,
                val pauseDays: Int = 0,
                val startDay: LocalDate = LocalDate.now())

The error is:

FATAL EXCEPTION: main Process: com.example.mytestapp, PID: 24087 java.time.temporal.UnsupportedTemporalTypeException: Unsupported field: HourOfDay

You are getting UnsupportedTemporalTypeException because you have defined your data with LocalDate. LocalDate doesn't have any information about the time and once you are trying to convert it to time, it causes a crash.

You need to update your data class Pill to have LocalDateTime instead of LocalDate:

data class Pill(
    val id: Int,
    val pillName: String,
    val yesDays: Int,
    val pauseDays: Int = 0,
    val startDay: LocalDateTime = LocalDateTime.now()
)