Absolutely!. If, however you are short of resources, set the timer to work with a soft switch, run for 20, change TH and TL, run for 1.5 etc. This way you only use one timer. While, in several situations it would not "hurt" to dwell for 1.5 mS inside an interrupt, you will somewhere down the road of your development start wondering why something does not quite work and after a long time it will strike you "oh last month I made a delay inside an interrupt, could that be it"

Have fun,

Erik