new_contents: import time
  import sys
  import datetime as dt
  from datetime import timedelta
  
  now = dt.datetime.now()
  h1 = str(now.hour)
  m1 = str(now.minute)
  s1 = str(now.second)
  
  print("User manual: Enter time in correct format! Program will use standard values otherwise. \n")
  
  # arrival time
  while True:
      try:
          t_in =str(input("Please enter time of arrival in format h:mm, thanks: "))
          t_in_h, t_in_m = t_in.split(':') 
          val1 = int(t_in_h)
          val2 = int(t_in_m)
          break
      except (ValueError):
          t_in_h = "06"
          t_in_m = "00"
          print("No or wrong input - using standard time - 6:00")
      break
  
  # work time    
  while True:
      try:
          t_work = str(input("Please enter expected work time in format h:mm: "))
          t_work_h, t_work_m = t_work.split(':') 
          val3 = int(t_work_h)
          val4 = int(t_work_m)
      except (ValueError):
          t_work_h = "08"
          t_work_m = "00"
          print("No or wrong input - using standard time - 8:00")
      break
      
  # lunch break
  while True:
      t_lunch = str(input("Do you have standard lunch break? y(enter)/n: "))
      if t_lunch == "n":
          t_lunch1 = int(input("How long was your lunch break? Minutes:"))
      else:
          print ("Using standard lunch time - 30 minutes")
          t_lunch1 = int("30")
      break
  
  #variables preparation
  t_now = h1 + ":" + m1 + ":" + s1
  t_ar= t_in_h + ":" + t_in_m + ":00"
  t_m = dt.timedelta(minutes=int(t_work_m)) + dt.timedelta(minutes=int(t_lunch1))
  t_w_h, t_w_m, t_w_s = str(t_m).split(':')
  time_working = str(int(t_work_h) + int(t_w_h)) + ":" + str(t_w_m) + ":00"
  fmt = '%H:%M:%S'
  
  #time values calculation and check
  time_lost = dt.datetime.strptime(str(t_now), str(fmt)) - dt.datetime.strptime(t_ar, fmt)
  time_lost1 = dt.datetime.strptime(str(time_working), str(fmt)) - dt.datetime.strptime(str(time_lost), str(fmt))
  time_home = dt.datetime.strptime(str(t_now), str(fmt)) + time_lost1
  time_print = dt.datetime.time(time_home)
  check = int(str(time_lost1.days))
  
  if check < 0:
      print ("What are you doing here? GO HOME!")
  else:
      print ("You can leave in:", time_lost1, "that will be at", time_print)
  exit()
  
subject: Create time.py