diff --git a/stringify.js b/stringify.js
new file mode 100644
index 00000000..15cfbe51
--- /dev/null
+++ b/stringify.js
@@ -0,0 +1,39 @@
+'use strict'
+
+const moment = require('moment-timezone')
+
+
+
+const date = (tz, when) => moment(when).tz(tz).format('YYYYMMDD')
+const time = (tz, when) => moment(when).tz(tz).format('HHmmss')
+
+
+
+// filters
+const bike = {type: 'BC', mode: 'INC'}
+const accessibility = {
+	  none:     {type: 'META', mode: 'INC', meta: 'notBarrierfree'}
+	, partial:  {type: 'META', mode: 'INC', meta: 'limitedBarrierfree'}
+	, complete: {type: 'META', mode: 'INC', meta: 'completeBarrierfree'}
+}
+
+
+
+const coord = (x) => Math.round(x * 1000000)
+const station = (id) => ({type: 'S', lid: 'L=' + id})
+const address = (latitude, longitude, name) => {
+	if (!latitude || !longitude || !name) throw new Error('invalid address.')
+	return {type: 'A', name, crd: {x: coord(longitude), y: coord(latitude)}}
+}
+const poi = (latitude, longitude, id, name) => {
+	if (!latitude || !longitude || !id || !name) throw new Error('invalid poi.')
+	return {type: 'P', name, lid: 'L=' + id, crd: {x: coord(longitude), y: coord(latitude)}}
+}
+
+
+
+module.exports = {
+	date, time,
+	bike, accessibility,
+	coord, station, address, poi
+}