Zotero writes timestamps as 'YYYY-MM-DD HH:MM:SS' internally but the sync engine requires ISO 8601 'YYYY-MM-DDTHH:MM:SSZ'. Six AFTER INSERT/UPDATE triggers on the items table auto-convert dateAdded, dateModified, and clientDateModified on every write. Includes fix_zotero_dates.py script to apply triggers and fix existing bad dates. Safe to run repeatedly.