O'Reilly is running a special deal for Celebrate SysAdmin Day. For one day only, SAVE 50% on a wide range of system administration ebooks and training videos from shop.oreilly.com. If you scroll down to page 18, you'll find Time Management for System Administrators is included.
50% off is pretty astounding. Considering that the book is cheaper than most ($19.99 for the eBook) there's practically no excuse to not have a copy. Finding the time to read it... that may be another situation entirely. I hate to say "you owe it to yourself" but, seriously, if you are stressed out, overworked, and under appreciated this might be a good time to take a break and read the first chapter or two.