In OH3, now() returns a java.time.ZonedDateTime. You can also get the current time by creating an instance of DateTimeType, which also has a zonedDateTime method to get a ZonedDateTime. A ZonedDateTime has a format method that takes a DateTimeFormatter and returns a formatted string…
import java.time.format.DateTimeFormatter// put at top of file
...
iPhone_Andzia_Home_full.postUpdate(aktual4 + " od " + now().format(DateTimeFormatter.ofPattern("HH:mm,dd.MM")))