This code works for me with latest version 3.1.45. Edit as needed to meet your GUI.
${title}
${startDate(%b %d %Y)} [!a:${startDate(%I:%M%p)}-${endDate(%I:%M%p)}][a: - All Day]
${title}
${startDate(%b %d %Y)} [!a:${startDate(%I:%M%p)}-${endDate(%I:%M%p)}][a: - All Day]