Do we need "at" before "around 7 AM" as in "I go to work (at) around 7 AM"?
We got these examples in this dictionary
around /əˈraʊnd/ adverb
We got home at around 8 o'clock. = (US) We got home around about 8 o'clock. [=it was approximately 8 o'clock when we got home]
We also got these examples in this dictionary
He arrived (at) about ten.
I don't understand why they use "around" & "about" together. So they use 2 adverbs "around" & "about", which have same meaning, next to each other