Data restoration utilizing forward and backward deltas

A restoration technique includes storing a collection of blocks having (i) a first baseline of blocks defining a file at a first time within a predefined window, (ii) older blocks, and (iii) newer blocks. The technique further includes providing a direction signal to restore the file at a particular time from the collection of blocks. The direction signal has an older direction value when the particular time is older than the first time and (ii) a newer direction value when the particular time is newer than the first time. The technique further includes forming, from the collection of blocks, a second baseline of blocks from the first baseline of blocks and additional blocks. The additional blocks are either (i) the older blocks or (ii) the newer blocks depending on the direction value. The second baseline defines the file at the particular time.