He was ill, so he lay in bed all day long.
TTS is incorrect and the transcript is correct. 一日中 should be pronounced as いちにちじゅう, not ついたちちゅう. ついたちちゅう means “(to be done) by the first day of (a certain month)” while いちにちじゅう means “all day long”.
Also We don’t usually write it as １日中 but 一日中 (i.e. all characters in Kanji) even if it’s in horizontal writing. I saw the same bad pattern in Tatoeba again and again, but don’t copy that.