linkgit:git-clone[1]), deepen or shorten the history to the specified
number of commits. Tags for the deepened commits are not fetched.
+--deepen=<depth>::
+ Similar to --depth, except it specifies the number of commits
+ from the current shallow boundary instead of from the tip of
+ each remote branch history.
+
--shallow-since=<date>::
Deepen or shorten the history of a shallow repository to
include all reachable commits after <date>.