I think the translation "they are changing every day" should also be an option. I learned during this two years with my Dutch language partners that for them the present tense can both mean present continues and normal present tense.
A simple example happened in IKEA. The lady asked 'Pardon meneer, ik zoek tafels.' By then I was still using 'ik ben een tafel aan het zoeken' which appeared to be not so commonly used daily then the former.
I wonder whether my understanding is correct. Any input will be appreciated.