print how long you have left in your daily colab session. Naive counter

left.py

import sys, json
from dateutil.parser import parse
from datetime import datetime, timezone, timedelta
with open("/var/colab/app.log", 'r') as fileData:
  for textline in fileData:
    if " started" in textline:
      time = parse (json.loads(textline)['time'])
now = datetime.now(time.tzinfo)
later = time + timedelta(hours=4)
print(now-time, "session started")
print(later - now, "left, based on the 4 hours a day free plan,\nthis does not include any other time used today")