• Date in java is stored in the form of a Long number. This long number holds the number of milli seconds passed since 1st Jan, 1970.
• Java assumes that 1900 is the start year which means it calculates years passed since 1900 whenever we ask it for years passed.
• System.currentTimeMillis() returns number of milli seconds passed since 1st Jan, 1970. Once milliseconds are calculated we can calculate minutes, seconds and years passed.

val milliseconds: Long = System.currentTimeMillis()
val minutes = milliseconds / 60000
val seconds = milliseconds / 1000 //1 sec = 1000 ms
val hours = milliseconds / 3600000
val days = milliseconds / (24 * 60 * 60 * 1000)
val years = days / 365