Translation:They work from Tuesday to Thursday.
So, when talking about time, the term before kadar is included in the range, but when talking about space, it is excluded. Am I understanding that correctly? For example, in the given sentence, Thursday is included in the days they worked, but in the phrase "onlar bahçeye kadar gittiler," they went up to or as far as the garden but didn't actually set foot in it. Is that correct?