What makes you say that? Just because it's Sunday? A planet square must be done it it's say and and it's hour for this you need to use a software such as ChronosXp to download it and put your cordonates there, your city and then start the square as the planet hour which would be let's say Sunday for Sun at Sun's hour which is 4 times a day the best time to start Sun Square would be around afternoon after 12:00 , Sun is strongest in it's best period abut 12-15:00 when is it strongest but you can start the square in the morning or evening as well, also avoid vid moon.
I would say it's a neutral , not good not bad , Sun is in Virgo right now so you could do Sun Square anytime you wish with the exception when it is in Aquarius or Libra.
Yea, you could do the material one and use an affirmation for wealth and wealth will come trough some other areas not just the one you mention , it might be anything , lottery , all of the sudden you receive help from family,friends and opportunities just appears to you.