Differences of expressions “on/behind/ahead of schedule”

Differences of expressions “on/behind/ahead of schedule”

1. “on schedule” is “just in time”. As scheduled. Not too soon nor too late.
2. “behind schedule” is “(too) late”
3. “ahead of schedule” is “too soon (/(too) early)”

Examples:

• “I am sorry Mr. president, we are running behind your schedule.”
• “The airplane has to take off now, we are already running behind our schedule.”

Reference:

https://www.italki.com/question/58232?hl=es