Is there a glitch on the bitcoin blockchain? Strange need clarification

I'm a bit confused here, maybe I’m not getting the blockchain right. How come block 839972 and block 839973 have timestamps that are earlier than block 839971? Would appreciate any explanations. Thanks, Louis.

See: https://en.bitcoin.it/wiki/Block_timestamp Timestamps only need to satisfy the following: "A timestamp is accepted as valid if it is greater than the median timestamp of previous 11 blocks, and less than the network-adjusted time + 2 hours. "Network-adjusted time" is the median of the timestamps returned by all nodes connected to you. As a result block timestamps are not exactly accurate, and they do not need to be. Block times are accurate only to within an hour or two."

Ok, I see, many thanks for the explanation.  Does make sense, regards, Louis

I also had a similar question sometime back, so this thread[1] might also be worth looking in to for any one looking for further answers. Some members there gave some excellent responses. 1. What is with these Bitcoin blocks?