Based on block timestamps (which do not have to be accurate), the longest difference between successive blocks is 463160 seconds (5 days, 8 hours, 39 minutes, 20 seconds) between blocks 0 and 1.

Block 0 : 2009-01-04 01:15

Block 1 : 2009-01-09 09:54

ที่มา : https://bitcoin.stackexchange.com/questions/77783/shortest-and-longest-block-interval-time-ever-recorded-in-bitcoin