MongoDB has introduced low-level timestamps in its WiredTiger storage engine to enable queries based on time and order, allowing snapshots to be created from a common point in time. This change reconciles the two ideas of order in the server and storage layer, ensuring that MongoDB's concept of time can be queried for data retrieval. Timestamps are now stored as metadata within the update structures created by WiredTiger, enabling the use of timestamps with queries to retrieve data at a specific moment. The addition of timestamps simplifies replication rollbacks by allowing servers to drop changes made after a majority commit point, reducing the complexity of synchronizing a server with the rest of the cluster. This change has enabled the use of WiredTiger's multi-version concurrency control to reduce locks and streamline resynchronization processes, giving the server the ability to roll back to a specific point in time for transaction correctness guarantees.