Translations:System Settings/Date & Time/3/en

From KDE UserBase Wiki

You can also set the date and time manually by deselecting the Set date and time automatically option. You then either select the date from the calendar or enter it in the text field below the calendar. You set the time by clicking on the part (hour, minute, or second) that you want to change in the field below the clock, and then either change the value using the arrows or simply type the proper value.