I always understand prepositions by thinking of their physical interpretations. "In" describes containment: "The water is IN the bottle" "On" describes precise location on top of something: "The cat is ON the table." "In time" and "on time" are no different. "On time" describes precise location of an event in relation to time: neither late nor early. "In time" works just like other "in" metaphors like "in love" and "in trouble". In each case, the "thing", be it love or trouble or time, acts like a container, a sort of kingdom in which you may or may not comfortably live. When you are "in love", you are in the Love Kingdom. What a nice place to be! When you are in "trouble", you are in the Trouble Kingdom, not a good place. When you are "in time", you are in harmony with the Time Kingdom. It doesn't indicate any sort of precision, just that that's a fine place for you to be. So if someone says they arrived "in time for the show", it doesn't mean that the show will start very soon. It only means that time is no problem, as far as seeing the show is concerned.

in: inside on: on top of that exact moment To arrive 'in time' means within that period and before the deadline (if the appointment is at 9am, you could arrive at any time before that: eg. 8:45, 8:50 or 9am).

“On time” is used to describe the present, someone is “on time”, or “late”. “In time” is rarely grammatically correct, unless you are referring to a specific point with relatively to a timeline. For example “In this specific moment in time, I will be at Paddington Station.” But it is more common to say. “At 1900 I will be at Paddington Station.”

Hi Sasha! Here’s how you can think about “in time” vs. “on time”: On time means punctual or VERY close to the scheduled moment. "On Time" Example: I arrived on time for my 9 AM meeting. This means I likely arrived a few minutes early and was ready for the meeting to start. In time also means arriving before it’s too late, usually with some extra time to spare. "In Time" Example: I arrived in time to grab a coffee before the meeting started. This means I arrived early enough to do something else (in this case, buy a coffee) before the meeting started. Hope that helps.