How to Build a Smart Calendar Blocking System

This smart calendar blocking system for focus time automatically protects deep work hours and adds prep time before meetings. Your calendar should serve you, not control you.

What You Need Before Starting

• Python 3.8+
• Google Calendar API credentials
• Flask for webhook endpoints
• SMTP or Slack for notifications

Step 1: Connect Calendar API

Set up access to Google Calendar or Outlook.

from google.oauth2.credentials import Credentials
from googleapiclient.discovery import build

def get_calendar_service(creds_path):
    creds = Credentials.from_authorized_user_file(creds_path)
    return build("calendar", "v3", credentials=creds)

def get_events(service, time_min, time_max):
    events = service.events().list(
        calendarId="primary", timeMin=time_min, timeMax=time_max,
        singleEvents=True, orderBy="startTime"
    ).execute()
    return events.get("items", [])

Step 2: Build the Logic

Implement the core calendar blocking algorithm.

from datetime import datetime, timedelta

def find_available_slots(events, date, duration_minutes=30):
    busy = [(e["start"]["dateTime"], e["end"]["dateTime"]) for e in events]
    slots = []
    current = datetime.combine(date, datetime.min.time().replace(hour=9))
    end_of_day = current.replace(hour=17)

    while current + timedelta(minutes=duration_minutes) <= end_of_day:
        slot_end = current + timedelta(minutes=duration_minutes)
        is_free = all(slot_end <= b[0] or current >= b[1] for b in busy)
        if is_free:
            slots.append({"start": current.isoformat(), "end": slot_end.isoformat()})
        current += timedelta(minutes=15)
    return slots

Step 3: Handle Notifications

Send confirmations and updates automatically.

def send_calendar_notification(event, recipients, notification_type):
    templates = {
        "confirmed": "Your {event_type} is confirmed for {time}",
        "reminder": "Reminder: {event_type} in {minutes} minutes",
        "cancelled": "{event_type} has been cancelled",
    }
    message = templates[notification_type].format(
        event_type=event["summary"], time=event["start"],
        minutes=event.get("reminder_minutes", 15))

    for recipient in recipients:
        send_email(recipient, f"Calendar: {event['summary']}", message)

Step 4: Store and Track

Keep a log of all scheduling actions.

import sqlite3

def log_scheduling_action(action_type, event_data):
    conn = sqlite3.connect("scheduling.db")
    conn.execute("""INSERT INTO schedule_log
        (action, event_id, details, timestamp)
        VALUES (?, ?, ?, ?)""",
        (action_type, event_data["id"], json.dumps(event_data), datetime.now().isoformat()))
    conn.commit()

Step 5: Automate the Workflow

Set up triggers and cron jobs.

# Run scheduling checks every 15 minutes during business hours
*/15 8-17 * * 1-5 cd /root/scheduler && python check_schedule.py

def run_scheduled_checks():
    service = get_calendar_service("creds.json")
    events = get_events(service, datetime.now().isoformat(), (datetime.now() + timedelta(hours=1)).isoformat())
    for event in events:
        check_and_notify(event)

What to Build Next

Add energy-level preferences. Block deep work during peak hours.

Related Reading

• The Automation Decision Tree - automation decision tree framework
• Building Your First Automation: A Complete Guide - first automation guide business
• The Automation Myth - automation myth business