The original sentence is:
周末那两天他看电视。
周末那两天 means both Sunday and Saturday?
周末那两天
literally means Those two days of the weekend
, hence, Saturday and Sunday.
However, numbers in Chinese is not always real numbers.
I think 周末那两天
could mean not only exactly those two days of the weekend, but also any day of those two days, maybe both of them.
Therefore, 周末那两天他看电视
could mean
He watches TV on Saturday and Sunday
He watched TV on those two days of the weekend
He (often) watches TV on weekends
More contexts are essential to understand a sentence precisely.
I would say yes to your question, if you think the whole weekend is made up of two days Sat and Sun.