• 暦こよみ — calendar; almanac
• 陰暦いんれき — lunar calendar
• 旧暦きゅうれき — old calendar (traditional lunar-solar)
• 新暦しんれき — new calendar (Gregorian)
• 西暦せいれき — the Western calendar; Common Era (CE)
• 和暦われき — Japanese era calendar (年号)

Built on the sun radical 日, 暦 organizes days and months. It pairs naturally with 歴 (“record / pass through”), giving words like 歴史 (history) and suggesting the passage of time. As a result, 暦 appears in systems that count time: lunar 陰暦, Gregorian 西暦, and era-based 和暦.