SleepUntil

This allows you to give a time to wait until, plus a number of days if desired:

sleepuntil 0:30 # wait until 0:30
sleepuntil 0:30 1 # wait 1 day, then wait until 0:30

The source. Note that half of the following code is just there for the sake of pretty-printing the magnitude of the time delay.

#!/usr/bin/env python3

import sys
from datetime import datetime
from time import sleep


args = sys.argv[1:]

if len(args) < 1 or len(args) > 2:
  print("""sleepuntil time
where time has format 12:34""")
  exit(1)

def parse_time(x):
  a = x.split(":")
  if len(a) < 2 or len(a) > 3:
    raise ValueError("Time should be in the format hh:mm or hh:mm:ss")
  if len(a) == 2:
    h,m = map(int,a)
    s = 0
  else:
    h,m,s = map(int,a)
  return (h,m,s)

def compute_secs_until(x):
  h,m,s = parse_time(x)
  now = datetime.now()
  h1 = now.hour
  m1 = now.minute
  s1 = now.second
  secs = 3600*h+60*m+s
  secs1 = 3600*h1+60*m1+s1
  dt = secs - secs1
  if dt < 0:
    dt += 24*3600
  return dt

def do_sleep():
  secs = compute_secs_until(args[0])
  if len(args) > 1:
    days = int(args[1])
    secs += 24*3600*days
  d = secs // (24*3600)
  h = (secs % (24*3600)) // 3600
  m = (secs % 3600) // 60
  s = (secs % 60)
  hms = []
  if d > 0:
    hms.append(f"{d} day")
    if d != 1:
      hms[-1] += "s"
  if h > 0:
    hms.append(f"{h} hour")
    if h != 1:
      hms[-1] += "s"
  if m > 0:
    hms.append(f"{m} minute")
    if m != 1:
      hms[-1] += "s"
  if s > 0:
    hms.append(f"{s} second")
    if s != 1:
      hms[-1] += "s"
  if len(hms) == 0:
    t = "0 seconds"
  elif len(hms) == 1:
    t = hms[0]
  else:
    hms1 = hms[:-1]
    hms2 = hms[-1]
    t = f"{', '.join(hms1)} and {hms2}"
  print(f"Sleeping {secs} seconds == {t}")
  sleep(secs)

if __name__ == "__main__":
  do_sleep()