Tsuki-okure means that under the Gregorian calendar (the New Style), dates of annually scheduled Japanese programs or events are deferred one month compared to the Taiin-taiyo-reki (lunisolar calendar) (the Old Style including the Tenpo calendar, the Kansei calendar, the Horyaku calendar, and the Jokyo calendar).
月遅れ（つきおくれ）とは、日本の年中行事の日程を太陰太陽暦(旧暦の天保暦、寛政暦、宝暦暦、貞享暦など)の日付からグレゴリオ暦(新暦)上で1か月遅らせて行うこと。