Updating the airport database
=============================

(1) Download timezone shapefile

Pick the latest timezones.shapefile.zip from
https://github.com/evansiroky/timezone-boundary-builder/releases

Extract combined_shapefile.shp from that zip file into this folder.

(2) Generate timezone lookup map

Open timezones.qgs in QGIS. Select "Project" > "Print Composers" > "timezone_lookup_map" and then
"Composer" > "Export as Image". Choose "timezones.png" in this folder and 2400dpi.

(3) Run the code generator

Run `make rebuild-knowledgedb` in the build dir of this folder.
