Hi Jonathan,
Yes `continuation` indeed accepts timestamps. It can thus be used as an `older than` limit of sorts.
Also recently added: `newerThan` accepts negative numbers to simplify syncing and avoid client/server clock differences. E.g. `newerThan=-3600000` indicates you only want articles added in the past hour (the value is in milliseconds, as usual).
You could in theory pass EPOCH timestamps in `newerThan` and `continuation` to fetch a "time slice", as long as these values are within the past 31 days (which is the limit for `newerThan`).
Hope this helps,