If you are Canadian, Spitfire (Maple Leaf fan, and a holder of TFSA, so I presume you are) the last day for tax loss selling on the TSX is December 27th this year.  You can read about it here:

https://www.tsinetwork.ca/daily-advice/how-to-invest/capital-gains-in-canada-what-is-tax-loss-selling-2/

And no, if you re-purchase those shares in a different account (RRSP or TFSA), then you do not need to wait the 30 days to repurchase them.

So, if you sold on the last possible day this year - December 27th - then you could repurchase them in your TFSA on January 2, 2018.

If you do not have Capital Gains in the past 3 years in which to offset the loss, then you can carry the loss forward indefintely, but only in your cash account.  The gains in your TFSA, of course, are tax free forever.   Or until some stupid government of the future deems otherwise.