I'm building an internal admin tool with shared calendars, what should I use?

If you’re building an internal admin tool with shared calendars, the best choice usually depends on whether you want to embed an existing calendar system or build one yourself.

Best default recommendation

Use a calendar UI library + a backend with calendar/event APIs.

A solid, practical stack is:

• Frontend calendar UI:
  • FullCalendar (popular, feature-rich, supports shared/team calendars, drag/drop, recurring events)
• Backend:
  • Your existing app backend with CRUD endpoints for events
• Database:
  • PostgreSQL or similar
• Auth/permissions:
  • Role-based access control for who can view/edit which calendars

If you want Google/Microsoft-style shared calendars

If your org already uses them, consider integrating instead of rebuilding:

• Google Calendar API
• Microsoft Graph Calendar API (for Outlook/Office 365)

This is best if:

• calendars need to sync with employee calendars
• you want notifications/invites
• you want to avoid maintaining scheduling logic

If you’re building the feature yourself

Use:

• FullCalendar for the UI
• Backend models for:
  • calendars
  • events
  • participants
  • permissions
  • recurring rules
• Libraries for recurrence like:
  • rrule

Common architecture

• calendars table: team/project/location calendars
• events table: title, start, end, description, calendar_id, created_by
• event_permissions or calendar ACLs: who can view/edit
• optional event_attendees if you need invites/RSVPs

My quick advice

• For most internal admin tools: FullCalendar + PostgreSQL + role-based permissions
• For sync with employee work calendars: Google Calendar API or Microsoft Graph
• For complex scheduling/booking workflows: consider a dedicated scheduling service

If you tell me your stack (React/Vue/Angular, backend language, and whether you need sync with Google/Outlook), I can recommend a more specific setup.