# "us" units on relaxation times $T_j$ in the IBM backends

A pretty lame question but, the backends relaxation times $$T_1,T_2$$ are given in us units. What are those? (Frequencies are given in GHz... Is it really $$\mu s$$ but IBM can't display the $$\mu$$ in the information chart?)

It's very common to write $$\mu s$$ as $$us$$, e.g. because it can be typed more easily. Sometimes it's forced by some software constraint (e.g. fixed width fonts often become not-fixed-width if you stray outside ASCII).