Keep your Christmas-heart open all the year round.

The line urges readers to treat the generosity, warmth, and attentiveness associated with Christmas not as a seasonal mood but as a durable ethical stance. A “Christmas-heart” suggests an inner disposition—openhandedness, forgiveness, and fellow-feeling—that can be practiced daily rather than performed annually. The imperative “keep … open” frames kindness as an ongoing discipline: one must resist the tendency to close off emotionally after the holidays and instead sustain hospitality toward others’ needs. In this sense, the quote participates in a long tradition of Christmas moralizing (popularized especially through Victorian literature) that treats the holiday as a prompt to extend compassion beyond one’s immediate circle and beyond the calendar.