The word 日子 is formed by combining the character 日, which pictographically represents the sun and by extension a single day, with 子, a character often used as a nominal suffix that gives a sense of a concrete or generalized entity. Together, they create a conceptual blend where the literal "sun" or "day" (日) is extended into a more substantive, countable unit of time or lived experience (子), effectively forming the idea of "days" as the tangible, passing units that make up one's life or calendar.