There is a right time for everything. The more you become attuned to the natural rythm of life the more you will come into the power of action supported by the Elemental Forces. This is something you cannot touch and know with your minds but only understand with you intuition. But since you still generally function and act guided by your minds, intellect and thinking, it is usually easiest for you to approach something new with via that authority. Once your minds are satisfied, believing to be in charge of a situation, it is much easier for your intuition to come in. Therefore we will start with an example comprehendable to the intellect.
Let us look at your seven days weeks. The names of the respective days give you some clue as to their meaning, the energy they contain- although not in all of your languages their roots are equally easy to derive.
Monday (lundi in French) is the day of the Moon. The Moon is a subtle influence, can be equalled with you intuition and feelings, ruled by the Element of Water. Because you may feel rather more sensitive than on other days, this is a day for quiet introspection and calm past-times. The ideal day also to learn to listen more to the voice of your heart, the intuition.
Tuesday, mardi in French, is the day of Mars. This on the other hand, is a day suited for out-going action, meeting responsibilities bravely and tackling to-do lists. Energy runs high and if you are in harmony within your-self and your life, much can be achieved on such a day- but on the other hand, if in disharmony the opposite applies.
Wednesday, mercredi in French, is the day of Mercury. You will find that on those days you often have many things to get done, many change of places, travelling to and fro. Also new people might appear in your life, be it by meeting personally, phone calls or e-mails.
Thursday, jeudi in French, the day of Jupiter. This day stands under a positive influence, a benevolent star, making it ideal for new ventures, going out or just simply working at home- suited for anything, really.
Friday, the day of Venus, vendredi in French, stands for beauty, art, Nature, Love. Therefore whatever they mean to you is suited for that day of the week.
Saturday, the day of Saturn. Although this day of the week is generally keep free from work, being part of the week-end, actually it is a very good day for diligent and productive working and business meetings- given that one is in a state of reasonable inner harmony.
Sunday, being the day of the Sun, make sit the ideal day for restorative past-times that feed the soul. So very much a day to be spent in a warm familiar/family atmosphere, but anything that makes you feel happy and contented with your-self is suited to that day.
We have now given you a general out-line, the original meaning and some associations to each day of your week. By reading up on some background literature on the planetary beings involved and by being observant of your-self each day of the week, you will find out a lot more about them, which in turn will enable you to design your weekly schedules much more efficiently. Respecting the days inherent energy is going to render your every-day life more harmonious. Of course, this system is a lot more complex and by looking at the day of the week only is a simplification because there is the monthly rythm of the moon plus the yearly gradiant of the sun to be taken into the account, too, plus your own horoskope... But to start with observing the week-days in relation to the respective phase of the moon as well as your-self is quite enough. Buying an accurate moon calendar might also help you to sensitise your-self further to the natural tides of cosmic life energy. But as a rule: never just believe what someone else has written or said- even if it comes from a well-studied person- because every single one of you is different- make it a rule to always counter-check with your own observance, experiences and awareness. You never know- maybe the author or the printing-press has made a mistake?