It's not possible, but you can fake it as dop2000 suggested. But, you don't need a plugin for this
Get the time and date at regular intervals while game is being played and save in local storage ( every minute or so, because you don't know when a player will quit the game ).
Then, the next time game is started get the time and date as soon as it starts, then load the last time and date saved in local storage, and subtract that from this new date. Then just award number of points per each minute, hour of difference, whatever your want. Of course you will need to convert time and date to hours or minutes, depending on what you want to use as your unit of measurement