三天两头 三天兩頭

    sāntiānliǎngtóu

    1. Idiomliterally twice every three days (idiom); practically every day; frequently

    他三天两头就要去健身房锻炼。Tā sāntiānliǎngtóu jiùyào qù jiànshēnfáng duànliàn.He goes to the gym practically every day.