Calculate total hours for an Emacs timeclock log.

timeclock.awk

function toDateTime(date, time) {
    gsub(/\//, " ", $2)
    awkDate = $2
    gsub(/:/, " ", $3)
    awkTime = $3
    return mktime(awkDate " " awkTime)
}

/^i / {
    clockIn = toDateTime($2, $3)
}

/^o / {
    clockOut = toDateTime($2, $3)
    total += clockOut - clockIn;
}

END { print total/60.0/60.0 }