When it's cold and bleak, and the sun barely shines, it is tempting to wish the time away and yearn for warmer weather.  I have been heard to say that I wish I could go to sleep and wake up in April when the daffodils are out and spring is shining through.
But what a waste!  OK, it is time to wrap up warm, but there are still things to be done, opportunities to grab, and preparation for the future.
So focus on what you CAN do - so it's not time to walk on the beach, or sit outside in the sun. It's time to do the preparation so that when those days are here, you can enjoy them. 
Make a list of all the things that inspire you and get to it.  Set yourself some targets. Make the time productive.  Just don't wish the time gone.