Literary or Wu-dialect (Shanghainese, Suzhou-hua) word for 'today/now'. In Mandarin standard, 今天 has replaced it in everyday speech. You'll meet 今朝 in poetry, classical chengyu, song lyrics, and Mao Zedong's 《沁园春·雪》: '数风流人物，还看今朝.'
mistakes
Don't read 朝 as cháo here — that's the 'dynasty/court' reading. In 今朝 ('this morning/today'), 朝 is zhāo, the 'morning' reading.
