Reset uptime only not all counters

Is there a script to reset uptime only in user list because I don’t want to reset all counters I just want to reset uptime only and keep bytes in/out … is that possible or what?.. I hope someone replies to me … thanks…a picture to show what I want :

Why?

You should add picture to the post. Edit post and click Attachments.

Because I want to set limit uptime 3 hours for all users every day but I have to reset all counters and I don’t want to reset bytes in /out for each user … i just want to reset uptime so that the user can use his 3 hours every day that’s it.
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