This is the kind of problem where you could load the whole thing into Postgres and get the answer in about five seconds. In fact, let’s try it: postgres# createtable i18n_day2 (inputtimestampwith time zone); CREATETABLE postgres=# \copy i18n_day2 from /i18np/input.txt COPY1758 postgres=# selectinputat time zone'UTC', count(*) from i18n_day2 groupbyinputat time zone'UTC'having count(*) >= 4; timezone | count ---------------------+-------20XX-YY-ZZ HH:MM:SS | 4 (1row) I decided to censor the ...
