const timeframes = [
  {
    name: '1900-1920',
    range: [timestamp, timestamp] // you could also parse this from the name
    slug: 'timeframes/1900-1920',
  },
  ...
];

function filterDataByTimeframe(range, data) {
  return data.filter(item => {
    // logic to determine whether item is within range
  });
}

timeframes.forEach(timeframe => {
  const filteredData = filterDataByTimeframe(timeframe.range, results.data.allMarkdownRemark.edges);
  createPaginatedPages({
    pathPrefix: timeframe.slug,
    edges: filteredData,
  });
});