thirty-first day of the month

Mus musculus, the common house mouse

Rome wasn't built in a day

お誕生日おめでとうございます: happy birthday

“a hundred days of sermonizing, one fart” → a metaphor for how something that one has put great effort into can come to nothing after even a slight mistake, much as a hundred days of serious spiritual study can be lost to the winds

(literally) plan your day during the morning, plan your year during New Year's / early planning is the key to success