Timechainstats.com has a collector of every exchange so you can see them all in real time
Discussion
I look to nostr:nprofile1qqsfx5v0j80628v2euujzlxu60fve5tcgv7tneerdp2y4txhgykt2rqpzemhxue69uhhyetvv9ujumt0wd68ytnsw43z7gtg4xs's beautiful https://timechaincalender.com and call it good. Even if it ends up a wee bit high or low, it's always moving, so...good enough.