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

two persons / a couple, pair

二箇月: two months (duration)

(grammar) second person

erhu

twice; two times / (music) second (interval) / two degrees (angle, teperature, etc...)

twice / again