Recently I have been asked several times about this topic. I though perhaps the following information may help others as well;
There is no limit to the number of magical workings one can do in a day however keep in mind that all magical workings require energy and sustained focus. Spreading your energy and focus out over too many magical workings at once can cause each working to be less effective. You also do not want the magical workings to be counter productive to each other. Typically if more than one magical working is performed they are done in a specific order for a particular reason. For an experienced caster these can be done all in the same day and with little to no break in between. The prime example is a banishing followed by a cleansing and then some protection magic to finish. This is done when too much negative energy surrounds a person or situation. When first starting out it is best to focus on one magical working at a time. You will want to leave plenty of time between castings to ensure proper rest and rejuvenation as well as allowing enough time for the casting to take effect or work (this could be weeks). Until you gain enough experience to cast more than one magical working be sure to follow this advice otherwise you will be wasting a lot of energy and time due to failed or weak magical castings.