This is one case where the early bird doesn't get the worm, because, it doesn't matter. Whether morning, midday or evening, the number of calories you burn during a specific activity doesn't change.

This is a case where the early bird doesn't get the worm, because, it doesn't matter. Whether morning, midday or evening, the number of calories you burn during a specific activity doesn't change. Rather, the number of calories you burn generally depends upon your body composition, metabolism and food intake -- none of which are dependent on the time of day you choose to exercise.
Muscle Consumes Calories

Because muscle burns calories and body fat does not, the more lean muscle mass in your body and the lower amount of fat, means that you will burn more calories during physical activity. Additionally, the more muscle mass you have, the more calories you will burn when you are sitting in a chair, cooking dinner or sleeping.

When people diet, particularly when they are not also exercising, they lose weight but often sacrifice muscle mass. This compounds the difficulties of losing weight and keeping it off. Severely restrictive diets can reduce your metabolic rate by up to 30 percent.
This is, in part, why strengthening exercises are so critical to losing and maintaining weight. The exercises help you to preserve muscle and bone, boosting your metabolism.
Three Ways to Burn Calories

To better understand why the time of day you exercise does not affect the number of calories you burn, it is important to know how calories are used.

Basal Metabolism : This is the energy you use to keep your body alive. It accounts for 50 to 75 percent of your daily caloric expenditure. The energy is responsible for maintaining things like the beating of your heart, functioning of other organs, your brain's activities and temperature regulation.
Use the formulas below to calculate your approximate basal metabolic rate (BMR). There are different formulas for men and women because men, as a fact of life, start out with more muscle mass than women and therefore burn more calories through their basal metabolism.
Women : 655 + (9.6 X W) + (1.7 X H) - (4.7 X A) = BMR
Men : 66 + (13.7 X W) + (5 X H) - (6.8 X A) = BMR
(W= Weight in kg, H= Height in cm, A= Age in years)
To convert kg to pounds: weight in lbs divided by 2.2
To convert inches to centimeters: height in inches times 2.54

Digestion : This accounts for approximately 10 percent of the calories you use to process the food you consume. For instance, if you consume 2000 calories a day, you burn 200 of them by just digesting the food. In effect, eating helps you burn calories in the same way exercise does, just to a lesser extent.

Physical Activity : Anywhere from 15 to 40 percent of the calories you burn comes from all of the various activities you perform throughout the day. Physical activity is the single-most important component of caloric expenditure that you have full control of.

When people think of burning calories, they think of vigorous exercise, such as jogging or playing tennis. However, many people forget that all physical activity burns additional calories.
For instance, people who are taking the elevator instead of the stairs -- but are getting up extra early to exercise in the hopes of burning extra calories--may be cheating themselves because taking the stairs also burns calories. Even activities as simple as getting up to change the television channel instead of using the remote control burns calories.

Everyone is somewhat guilty of taking the easy route when it comes to getting somewhere or doing other activities. But, reminding yourself of the extra calories you are burning during the simplest tasks may help you to invoke healthier lifestyle habits by simply taking advantage of your own mobility.