which is what I did. its a way to break up the flash data space
enabling reading, writing and erasing of data in a pic sized way
yet deal with large data structures normally beyond a pic's scope.


search for the time/date wanted and download the missing information.
just looking at that requirement makes me think a sudo file structure
would be an enormous advantage ,
think of flash structure , 125 64k blocks , each block has 16 4k pages .

each page could hold 256 16 byte records depending on how many records per day/week whatever will fit in a block. eg. a new block[file] every fortnight
a new page every day sort of thing makes life easy
{its what i use , a record ever 6 mins) [if your storage is timed accurately the timestamp is redundant]
you can do a bit of wear levelling by offsetting the day page and have a simple ring structure