In hoodoo/rootwork/conjure specific times are considered important for both good or bad works. Below one can find a general guide to what times are used.
Dawn/Sunrise - For new beginnings and to draw things
Noon - For money, prosperity, success, and power
Dusk/Sunset - For cleansing, banishing, or repelling things
Midnight - For reversing work or enemy work
3pm - Considered by some to be a magical time that is good for any work.
7pm - Considered by some to be a time best for any good work
9PM - Considered by some to be a time best for domination work
"Dead Hour" - According to "Minerva" of Midnight In The Garden of Good and Evil fame, Dead Hour is the time from 11:30PM - 12:30AM. The first half hour is for any good work. The second half hour is for bad work. This is actually a form of "working by the clock".
Working By The Clock - When the clock hands are moving upwards it is the perfect time for any good work. When the clock hands are moving downwards it is for bad work or for banishing and reversing work.
Waiting For Sleep - When working on a specific person, and usually to influence the person's mind or behavior, many workers will wait for the person to go to sleep. Some workers will even wait for a person to go to sleep before they use enemy work on them. The reason being is that when a person is asleep they are more vulnerable to attack as well as are open to suggestion. When a person is asleep it is easier for a worker to get inside their mind and effect them subconsciously. The key thing to know is that the work must be done when the person is asleep. This means that the worker will need to know the habits of the person being worked on. If that person doesn't get off work until 2:00AM then the worker may not want to begin working on the person until say 3:00AM or 3:30AM.
Witches & Evil-Doers - It was also believed that witches (not Wiccans, Neopagans, etc.) or evil doers had their own special times. Witches and evil-doers preferred "The Witching Hour" (12:00AM - 1:00AM), as well as Dead Time/Hour Of The Wolf (3:00AM - 4:00AM) for doing black magic.