Add optional start and end date/time fields to blog posts so they can automatically go live and expire.
Why
Prevent posts going live too early or staying up too long
Reduce manual publishing/unpublishing (especially out of hours)
Improve accuracy for campaigns, events, and time-sensitive content
How it works
Post is visible after the start date/time
Post is hidden after the end date/time (if set)
If no end date is set, behaviour stays the same as now
Benefits
Cleaner, more reliable content
Less admin effort
Better control for marketing and campaigns
Notes
Times should be clearly labelled (e.g. UK time)
Expired posts should not appear in listings or search
