with c++, cmake, hhdate
Reads CSV header line, then consumes all the lines; Converts 4th field from string representation of form 'YYYY-mm-dd HH:MM:SS' to an internal numeric double representing seconds since UNIX epoch.
dummy1,dummy2,value1,timestamp
22,xyz,0.45,2020-01-30 12:33:01
10,abc,0.99,2020-01-30 12:33:02
$ ./test-1 tst.csv
CSV filename=tst.csv; number of fields=4
field number 1: name: dummy1
field number 2: name: dummy2
field number 3: name: value1
field number 4: name: timestamp
got a CSV line; 4th field (timestamp) value='2020-01-30 12:33:01'; numeric value=1580387581
got a CSV line; 4th field (timestamp) value='2020-01-30 12:33:02'; numeric value=1580387582