I know I commited some important changes to my repo the 1st of January of 2017, after that I've done some work but I've also accidentally deleted some commits.
Is it possible to recover or view deleted commits from an specific date, for instance, the commit of 01/01/2017?
As mentioned in a comment you can use git reflog
Also so you are aware, you can use the git pretty format with reflog so git reflog --pretty="format:%h %aD %s" will give you an output of commit ID, Date and commit subject.
To just expand on the comment. Once you find the commit you want, you can check the contents of a commit to make sure the commit is correct by doing something like this git show commitID.
Then you can either do a git merge commitID or a git cherry-pick commitID.
You may get some merge conflicts so just resolve them as normal.