can i use chi square for two ordinal variables I have two variables in my research survey, Variable 1(less than 6 hours,6-8 hours, more than 8 hours) and variable 2(not at all, several days, more than half the days, nearly everyday). I want to know if there's an association between them or not. Can I use chi square for these variables or should I use some other statistical test?

First make sure that the crudely categorized versions of those two measurements are all that were collected.   Then don't use a method such as Pearson's $\chi^2$ that ignores the ordinal nature of the variables.  Consider a rank correlation method such as Goodman-Kruskal $\gamma$ or one of the Kendall $\tau$s.  Be sure to quantify the degree of association and to downplay statistical "significance" which actually means quite little.  Also consider computing a confidence interval for the rank correlation measure to show sample size limitations.
