AtD translation: work on my sleep allowance

[Mike Jing]

P590.17-23   “They tell me you’re kind of famous?”
       “Women at Göttingen form a somewhat beleaguered subset.” She looked
around. “And what is it you do here again?”
       “Drink beer, work on my sleep allowance, the usual.”
       “I took you for a mathematician.”
       “Well . . . maybe not your kind. . . .”
       “Yes? Come, don’t be too clever.”

What does "work on my sleep allowance" mean?