The conditions of my research grant say that I must ensure open access to the peer reviewed publications describing project results by making them available in a repository "within twelve months of publication" (the accepted manuscript is enough).
Springer's conditions for the embargo period say "Authors may self-archive the author’s accepted manuscript of their articles on their own websites. Authors may also deposit this version of the article in any repository, provided it is only made publicly available 12 months after official publication or later."
Are these two things compatible? My understanding is that they are, because the day that comes exactly twelve months after publication is both the last day that is "within twelve months of publication", and the first day that is "12 months after official publication or later", so by making the publication available exactly that day I would be complying with both the funding agency and the publisher. But not being a native English speaker, I'm not 100% sure.