have_nice_day.py

import os
import twitter

from datetime import datetime, timedelta


def hello_cloudscheduler(event, context):
    # API keys
    consumer_key = os.environ['CONSUMER_KEY']
    consumer_secret = os.environ['CONSUMER_SECRET']
    access_key = os.environ['ACCESS_KEY']
    access_secret = os.environ['ACCESS_SECRET']

    api = twitter.Api(consumer_key=consumer_key,
                      consumer_secret=consumer_secret,
                      access_token_key=access_key,
                      access_token_secret=access_secret)

    timestamp = context.timestamp

    brt = datetime.strptime(timestamp, '%Y-%m-%dT%H:%M:%S.%fZ') - timedelta(hours=3)

    date = brt.strftime('%d, %b at %H:%M')

    api.PostUpdate(f'Have a nice day! \n\nToday {date}')