A stock phrase in Japanese pop culture supposedly used by the wife in a newly-wed couple to invite her new husband to bed.

Kyūjitai form of 私生児 (“illegitimate child”)

one day, 24 hours / the daytime, the period from dawn until dusk / (figuratively) a short period of time / one day, someday, an unspecified day / the first day of the month

a birthday

regular day off (e.g. closed every Monday)

幾日も幾日も: day after day

twenty; 20

(obsolete) twenty; 20

twenty; 20

decimal system