International Atomic Time (abbreviated TAI, from its French name ) is a high-precision atomic coordinate time standard based on the notional passage of proper time on Earth's geoid.
ˌɪntɚnˈæʃənəl ɐtˈɑːmɪk tˈaɪm ɐbɹˈiːvɪˌeɪɾᵻd tˌiːˌeɪˈaɪ, fɹʌm ɪts fɹˈɛntʃ nˈeɪm ɪz ɐ hˈaɪpɹɪsˈɪʒən ɐtˈɑːmɪk koʊˈɔːɹdᵻnət tˈaɪm stˈændɚd bˈeɪst ɔnðə nˈoʊʃənəl pˈæsɪdʒ ʌv pɹˈɑːpɚ tˈaɪm ˌɔn ˈɜːθz dʒˌiːoʊˈɪd.