Here are some ideas for taming the "arsenic hour," pre-dinner-time child-monster, gleaned from "FussBusters at Home":
Suggest that crabby kids go into the bathroom or outside and actually spit out all their grumpy feelings. You can even provide a cup of water for them to gargle and then spit out into the sink or out on the pavement.
Get kids to race around outside (or in a large inside room) to "run the bad feelings out of town."
Show kids how to transform themselves into "whizzers" by taking in great gulps of air that represent their angry feelings, holding the air in for a few seconds, and then letting it out in a whoosh.
Provide a snack (such as a small serving of veggies or some other food that you're preparing for dinner). Kids who are grumpy at this hour often are just hungry.
Keep a handy bag of toys to help distract your child. Not every toy works at this time of day. For example, "outgrown" toys can work well because many children regress when they're tired, while puzzles and other challenging games can increase the frustration level.
Find a way for your child to help you with dinner. Use themes -- your child can "swab the deck" (cleaning the table), be designated the "grog master" (getting drinks for everyone) or become a "cowhand" who loads up his "chuck wagon" to bring things to and from the table.