Yes, and no. It depends mainly upon the particular system you are working within and the spirit you are evoking. If you are working planetary magick for example, and are evoking the Intelligence of Jupiter, then yes, the day of the week and the planetary hour matter quite a lot. However, if you are evoking the demon Belial, then no, it doesn’t matter much.
When it comes to planetary or astrological correspondences, figuring out the most optimal time can get quite complicated but it is always better to evoke when the need arises than to wait for the perfect confluence of planetary alignment.