Every online casino profile page have the feature you seek for, if you are not satisfied with that there is nothing you can do about it because a tool like you wanted might not exists. If you want to track the time you spent or want to spend on a casino you can get a wristwatch or a time counter.

I don't need to track my gambling activities off the platform that I am using, everything should be clear on your profile, maybe for other gamblers who are too deep into gambling can have their ways but I don't see any need to find one, even outside the casino.

There is an app called gambling tracker: manage money and time on playstore if you are using android smartphone but mind you I've never used this app I've only heard about good reviews from users.