Currently, Business Calendar for Android occasionally fails to save or sync events when network conditions are poor or when users don't wait for the complete sync process. This results in data loss, which is unacceptable for calendar events that often represent critical business and personal commitments.

User Impact:
• Lost appointments and meetings
• Reduced trust in the application
• Need to re-enter data multiple times
• Risk of missing important commitments
• Additional time spent verifying if events were actually saved

Proposed Solution:

Implement a robust event persistence system with the following characteristics:

1. Local-First Storage:
   • Save events immediately to local storage before any sync attempt
   • Provide instant feedback when the event is safely stored locally
   • Use a local queue system for pending sync operations

2. Background Sync System:
   • Implement a reliable background sync service
   • Queue failed sync attempts for later retry
   • Use exponential backoff for retry attempts
   • Persist the sync queue across app restarts

3. User Interface Enhancements:
   • Clear visual indicators for sync status:
   Saved locally
   Syncing in progress
   Sync complete
   Sync pending
   • Option to view pending sync queue
   • Notification for persistent sync failures

4. Data Integrity Features:
   • Checksums for event data
   • Version control for conflict resolution
   • Audit log of save/sync attempts
   • Optional manual sync trigger

Success Metrics:
• Zero reported cases of data loss
• Successful sync rate > 99.9%
• User confidence in save operations
• Reduced support tickets related to lost events

Priority: Critical
This feature is essential for maintaining user trust and ensuring reliable operation of the calendar app in real-world conditions.

Additional Benefits:
• Improved offline functionality
• Better user experience in poor network conditions
• Reduced user anxiety about data loss
• Enhanced app reliability reputation

User Story:
As a business user, I want to be absolutely certain that when I create or modify a calendar event, it will be saved and synced, regardless of my current network conditions, so that I never lose important appointment data.

As a user who relies on calendar notifications, I want to be confident that when I set a reminder for an event, the notification settings will be properly saved and synced across all my devices, so that I never miss an important appointment due to missing notifications.