Great Consensus Cleanup Revival

An analysis of mainnet block retargets reveals that out of 483 instances spanning from block 2,016 to 973,728, there were only ten occasions where the first block of a new period was timestamped earlier than the last block of the preceding period. The most significant negative offset occurred at block 203,616 on 16 October 2012, with a discrepancy of -1,127 seconds. A grace period of 600 seconds would have resulted in the rejection of this block unless it was timestamped at or after 23:04:55. Since 2015, the largest negative offset recorded is -43 seconds at block 812,448.

No observed instance approaches a threshold of 7,200 seconds, and every period maintains a positive total span, indicating robust adherence to chronological order within block periods. For those interested in further examination, comprehensive data on each seam is available in a CSV file, which is referenced in an explanatory write-up accessible here.