This might be a bit a bizarrely specific question, but I attended a Reformed college and during one of our discussions in a course I've since forgotten I remember my professor mentioning in an offhand way that the early followers of John Calvin kept journals of their daily habits in an attempt to notice in those habits "evidences of grace" that would confirm their status as among the elect.
I haven't been able to find any scholarly information on whether this indeed occurred, but it seemed to strangely specific that I have a hard time imagining it to be entirely fabricated. Thanks for your time!
It's a big category, "followers of John Calvin". I'm not sure about Huguenots in France, Swiss Calvinists, German Calvinists.....However, certainly for the Puritans both in England and the English colonies in North America, there was a good bit of this- the theology brought the fear of already being damned, the hope of already being of the Elect, and writing in journals gave them at least something to do about it. One of the more famous examples in the colonies would be William Bradford, who as governor of the Plymoth colony kept a journal that has become a very important source for the early colony. Actually, in the early colonies of the 17th c. there has survived remarkably little writing in general ( they mostly were too busy with just simple survival) , and so the old Norton Anthology of American Literature even has some material from Puritan diaries in it, from William Brewster, Samuel Sewell and John Winthrop. For England, a very common source is M. M. Knappen's edition of Two Elizabethan Diaries by Richard Rogers and Samuel Ward , available online at the Hathi Trust-