Today 12.00 UTC might begin a possible Bitcoin blockchain fork to implement a larger block size and revert on the Segwit implementation (resources here : Details about the fork are visible here :

We at KeeeX have long committed to Bitcoin as the safest of all blockchains, and the fork would not impact previous timestamps and anchors (visible at, nor impact future anchors. We shall continue using the main Bitcoin chain in the near future, also because Segwit is meaningful to us, as it resolves the transaction malleability issue that when occurring would have impacted the access to our blockchain timestamps.

You can watch the event occur in real time at