Beijing/northern colloquial. Standard equivalent: 明天. Pattern extends across the calendar: 今儿个 (today), 昨儿个 (yesterday), 后儿个 (day after tomorrow), 前儿个 (day before yesterday).
memory
明儿 already means 'tomorrow' in Beijing speech; the 个 is a colloquial filler that adds rhythm. Tone: 儿 and 个 both go neutral.
