If you wanted courage in love, you would use a Mars hour on a Friday. If you needed to communicate your feelings, but found it difficult, you could add the energies of a Mercury hour to a Friday love spell.
If you wanted a banishing spell for shedding excess weight, you could use the last days of the waning moon cycle when it is in the sky during the morning before it sets. The banishing lunar energies should take away the compulsion to binge that is keeping you from a healthy lifestyle and if you use them at the hour of Venus, this would increase your inner beauty and help to bring you to a state of self-love.
Remember that the beginning of the hour is always the most potent. The times of sunrise and sunset are different each day. Calculate the precise timings from true sunrise, which is the first hour of the magical day. Alternatively, for a less formal spell, you can make an approximation.
Any good diary will have the sunrise and sunset for each day, but choose one also with the moonrises and moonsets. You will need a calculator if you decide to use the exact planetary hours.
You can calculate a week or even a month ahead if there is a period in which you intend to do a lot of magical work. In this way you can maximise the energies of specific hours and choose a good time for anything from asking for a rise at work to sorting out the budget with a reluctant partner.
Enter the planetary and angelic hours in your diary or the appropriate section in your Book of Shadows.
To calculate the magical hours, you need to divide the time from sunrise to sunset and then the time between sunset and sunrise by 12. At the height of summer, the days are much longer than the nights, so each 'day' hour will be longer than the 'night' hours.
At the spring and autumn equinoxes, when day and night are equal, day and night hours will be of the same length.
As a short-cut, when you need instant magick, you can use the times of sunrise, noon, sunset and midnight and the day of the week energies, with approximations of hours if you wish.
Combine the day energies with the power of solar magick, which tends to be more immediate than lunar. So if you are seeking a new beginning, go for dawn.
For full power or realising your potential, carry out your rituals at noon, the height of the Sun, and for banishing spells, try sunset. You will know instinctively if it's a solar or lunar issue and whether you need a blast of Sun power or clarity, or more subtle Moon bindings or unravellings.