Google Calendar settings tweaks can help make your calendar less stressful by displaying multiple time zones, fading past events, allowing quick undo of accidental changes, and viewing multiple calendars side by side. By making these adjustments, users can reduce mental math stress, avoid anxiety about full calendars, and gain more control over their scheduling. Additionally, Google Calendar can be connected to other apps through Zapier, automating processes such as copying new events to another calendar or generating detailed events from new Notion database items.