How important is the time I take my meds each day?

I feel you believe your medications interact negatively, actually according to Drugs.com they don't, ran an interaction check and this is what the result was:

Interactions between your drugs
No drug ⬌ drug interactions were found between the drugs in your list. However, this does not necessarily mean no drug interactions exist. Always consult your health care provider.

There are 2 moderate drug and food interactions.

Source: https://www.drugs.com/interactions-check.php?drug_list=890-1664,1987-1280

Coming back to your question, if you want to treat/control your HBP (Cartia XT) it is of crucial importance that you take it as prescribed by your DR., and the same goes for Evista and preventing:

"Evista affects the cycle of bone formation and breakdown in the body, and reduces loss of bone tissue.

Evista is used to treat or prevent osteoporosis in postmenopausal women. Evista is also used to reduce the risk of invasive breast cancer in postmenopausal women who have osteoporosis or who are otherwise at risk of invasive breast cancer.

Evista is not a cancer medication and will not treat breast cancer."

Source and more info:
https://www.drugs.com/cons/cartia-xt.html

https://www.drugs.com/evista.html

So, it is vital you take your meds, if you feel uneasy, do contact your DR. or his/her nurse in order to clarify your apprehensions, before the weekend.