import datetime
import time

set_time = datetime.datetime(2019, 12, 31, 19, 0)
now_time = datetime.datetime.now()
delta = set_time - now_time
sec_in_day = (delta.total_seconds() - delta.days*24*60*60)
hours = int(sec_in_day // (60*60))
minutes = int((sec_in_day - hours*(60*60)) // 60)
seconds = int(sec_in_day - minutes*60 - hours*60*60)

if delta.total_seconds() < 0:
    print("worng set_time")
else:
    print('Timer:', set_time)
    print(f'wait time: {delta.days}days {hours}h {minutes}m {seconds}s')
    time.sleep(delta.total_seconds())
    print("wryyyy!!!") # script start!