People use "Mat Time" expression all the time.
As in "You gotta put in the Mat Time in if you wanna get better" for example.
But what exactly is Mat Time?

So if I go to BJJ class at 6pm and I'm there till 7:30pm.
And there is 15 min warm up.
Then 30 min drilling.
Then six 5min rounds of rolling (30 min of rolling total).

Is my Mat Time for the day 1 hour and 30 min?
Or do I count only 30 min of rolling as Mat Time?

What do you guys think?

ps.
I know it is a silly question.... just thinking out loud.

It's not a silly question! No questions are

I think it can be compared with say an artist, This is Martial Arts after all.

An artist can make a painting or a sculpture and show it to someone and they might say "I think you need to give it more time". Its not a specific question about the amount of hours or the exact time. It rather means that you have to put in more time in general to get better.

As for how much time, it's probably "as much as possible". I mean wouldn't it be awesome to train 18 hours a day 7 days a week? But who can do that, practically nobody...

When it comes to the term "Mat time" I think people refer to experience on the mat, more than the actual exact hours training spent there. It's not the same "mat time" to lay on the mat for 4 hours or to train hard for two hours. Its not about the actual "Mat" its about getting the training in.

If someone says you need more mat time you probably need to add a day a week of grappling and wrestling training, for example.

Mat time could also refer to time spent on the mat actually competing and not just training. I think it depends on under what circumstances its mentioned.

Just my 2 cents...

I get it.

My advice would be: In the end it doesn't really matter what others consider "mat time" to be, so just make up your own system where you get the most out of it. You already seem to have figured out what is giving you the kick you need and what is making you "better". So thats probably what you should count as mat time for you! Who knows you might even be able to set some standards that others can use as well

OK.... chatting about this actually helped.
Me trying to explain what I mean actually crystallized the answer.
So I'd say: Mat Time is the time that is "getting me better at grappling".

Warm up and stretching is not Mat Time.
Watching Youtube videos is not Mat Time.

Grappling based Warm up (like Shadow Wrestling) is Mat Time.
Drilling is Mat Time, even if it is drilling at home on a Grappling Dummy.
Rolling and competing is Mat Time.

I like this definition a lot actually.
Especially because home Grappling Dummy Drilling is included in Mat Time.
I can do 15 min a day 4 days a week for an extra 1 hour of Mat Time weekly.
I can easily fit this into my workout schedule and counting minutes will keep me motivated and disciplined.

I think you nailed it! Well done!