TinyCal is a menu-bar calendar with Google Calendar integration. It can show multiple months, use custom calendars, and show holidays and personal calendars. The basic version of TinyCal is free. You can use it as much as you like with no time limitations or obligations. Advanced functionality is available at the published price. The full version offers the following features:

• Personal Google Calendar integration
• Unlimited public Google Calendars
• Customized event colors