No good per-sub way as of 2022:
- www.reddit.com/r/help/comments/27eziq/view_top_posts_of_a_specific_timespan/
- www.reddit.com/r/help/comments/9ebxl3/how_do_i_find_old_posts_on_a_subreddit/
- www.reddit.com/r/help/comments/aywras/how_do_i_search_reddit_for_posts_in_a_specific/
- www.reddit.com/r/modhelp/comments/etsomx/how_to_get_top_posts_of_past_months_of_subreddit/
- www.reddit.com/r/redditdev/comments/kaf1yz/finding_top_post_of_specific_month/
- www.reddit.com/r/changelog/comments/k663qy/introducing_rereddit_go_back_in_time_to_see_top/
- www.reddit.com/r/help/comments/stui9i/is_it_possible_to_look_up_the_top_posts_of_the/