Hello, how can I covert this string variable into Date to be like 2021-06-30

Code:
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clear
input str10 dob
"05aug2021"
"09aug2021"
"13aug2021"
"16aug2021"
"17aug2021"
"16aug2021"
"19aug2021"
"19aug2021"
"19aug2021"
"20aug2021"
"20aug2021"
"20aug2021"
"20aug2021"
"20aug2021"
"23aug2021"
"24aug2021"
"24aug2021"
"24aug2021"
"25aug2021"
"25aug2021"
"25aug2021"
"25aug2021"
"26aug2021"
"25aug2021"
"26aug2021"
"25aug2021"
"26aug2021"
"27aug2021"
"27aug2021"
"27aug2021"
"27aug2021"
"27aug2021"
"26aug2021"
"27aug2021"
"26aug2021"
"27aug2021"
"27aug2021"
"27aug2021"
"27aug2021"
"19aug2021"
"27aug2021"
"27aug2021"
"18aug2021"
"26aug2021"
"19aug2021"
"30aug2021"
"27aug2021"
"27aug2021"
"27aug2021"
"29aug2021"
"30aug2021"
"26aug2021"
"27aug2021"
"27aug2021"
"27aug2021"
"27aug2021"
"30aug2021"
"30aug2021"
"20aug2021"
"30aug2021"
"30aug2021"
"30aug2021"
"30aug2021"
"30aug2021"
"30aug2021"
"30aug2021"
"30aug2021"
"26jan2021"
"01feb2021"
"01feb2021"
"02feb2021"
"31jan2021"
"03feb2021"
"04feb2021"
"05feb2021"
"05feb2021"
"07feb2021"
"06feb2021"
"05feb2021"
"05feb2021"
"07feb2021"
"09feb2021"
"07feb2021"
"08feb2021"
"09feb2021"
"19feb2021"
"22feb2021"
"23feb2021"
"23feb2021"
"25feb2021"
"25feb2021"
"25feb2021"
"26feb2021"
"26feb2021"
"25feb2021"
"26feb2021"
"26feb2021"
"25feb2021"
"25feb2021"
"26feb2021"
end