Is it grammatically incorrect to use 'at about,' as in 'The incident occurred at about 10 p.m.' To me, 'at' means at a definite time; 'about' means around a certain time (approximately). Please meet me about 6:30. (Means somewhere around 6:30—give or take a few minutes either way.) Please meet me at 6:30. (Means at 6:30 on the dot.) But one could argue that 'Please meet me about 6:30' could mean that you're meeting me about (concerning) 6:30 itself. So are the expressions 'at about 6:30' and 'at around 6:30' correct or redundant? Would you use 'at about' and 'at around' in your writing? That said, are these correct (or should I use 'at' before 'about/around')? The incident occurred about 4:20 p.m. About 6 p.m. the incident occurred. The incident occurred around 2:40 a.m. Around 2:40 a.m. the incident occurred. Thanks.