old_contents: 'use strict';
  var time = require('time')(Date);
  var today = (time.time() - 7 * 24 * 60 * 60);
  var turf = require('turf');
  
  // Filter features that are touched in the last 7 days.
  module.exports = function(tileLayers, tile, writeData, done) {
    var layer = tileLayers.osm.osm;
    var result = layer.features.filter(function(obj) {
      return (obj.properties._timestamp >= today);
    });
  
    if (result.length > 0) {
      var fc = turf.featurecollection(result);
      writeData(JSON.stringify(fc) + '\n');
    }
  
    done(null, null);
  };
  
new_contents: 'use strict';
  var time = require('time')(Date);
  var today = (time.time() - 7 * 24 * 60 * 60);
  var turf = require('turf');
  
  // Filter features that are touched in the last 7 days.
  module.exports = function(tileLayers, tile, writeData, done) {
    var layer = tileLayers.osm.osm;
    var result = layer.features.filter(function(obj) {
      return (obj.properties['@timestamp'] >= today);
    });
  
    if (result.length > 0) {
      var fc = turf.featurecollection(result);
      writeData(JSON.stringify(fc) + '\n');
    }
  
    done(null, null);
  };
  
subject: update filterDate