Это было 16-20 мая 1971 года. А эта

Это было 16-20 мая 1971 года. А эта сессия была примерно неделей раньше (или - всё-таки позже?)

Результаты (английский) 1:

It was 16-20 May 1971 year. As the session was about the week before (or still later?)

Результаты (английский) 2:

It was 16-20 in May 1971. And this session was about a week earlier (or - still later?)

Результаты (английский) 3:

This was 16-20 May 1971. And this session was approximately a week earlier (or - still at a later date?)