I have seen countless questions asking about converting latitude / longitude coordinates into country, state, town, etc., but I found no question which includes a time component. I have tried many searches, but only seem to be able to get isolated data sources by year or real-time APIs, not any open source data with a time component.

As an example using United States recognition, the coordinates (42.635832, 20.946381) would show Kosovo today, but in 2005 would show Serbia, and would at some point further in the past show Yugoslavia.

What data source can be used to retrieve country from latitude, longitude, and date? The ideal granularity would be day, ideal source of authority would be US recognition. The ideal data format would be some sort of structured shape data with start and end dates for validity.

  • 4
    I once created a dataset to handle date of creation and boundary changes like this. It wasn't difficult, though it did complicate join modelling to add checks for start_yr and end_yr in each SQL statement. I'd expect you'd need to build this yourself, especially if you want to model exact day of status change. Obtaining standard boundaries across time is likely to be your largest challenge.
    – Vince
    Nov 30, 2022 at 16:08
  • @Vince That's rather frustrating, I would think that someone would have constructed this data set on at least a country/year level of granularity for open source use. I'll leave the question for a few days before giving up.
    – N. P.
    Nov 30, 2022 at 16:10
  • 1
    Maybe ask here: opendata.stackexchange.com
    – John Polo
    Nov 30, 2022 at 16:25
  • 1
    The US Department of State (Office of the Geographer) is responsible for definitive US recognition boundaries, but they do so at the line level, relative to NGA 1:100k shorelines (which keep evolving). NGA has the responsibility for distributing these boundaries to US government interests, but not externally. Successive releases of those boundaries shifted 10-30m recently, so just tracking boundary changes for the past 20 years was a major endeavor. But the real issue is that this is more of a discussion Question, and we're a Q&A site.
    – Vince
    Nov 30, 2022 at 16:26
  • Partial answer here, works roughly up to 1994: gislounge.com/find-gis-data-historical-country-boundaries
    – N. P.
    Nov 30, 2022 at 17:10


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Browse other questions tagged or ask your own question.