I either mark the time in some way (start a ritual you do on T day to recognize it and that time is passing and you'll see her in 7, 6, 5, 4. . . weeks :-) or I plan something for beyond when I'll see her again; a trip/vacation or activity I've been planning/looking forward to while she was away; my T was once gone over 12 weeks and I decided to write her a novel! Start a large project that can only be done because she is away and be "glad" she is away.