render_astronomy: fix sun ephem for daylight savings time

src/render.js

@@ -221,10 +221,6 @@ export function render_astronomy(canvas, width, height, offset, data) {
         .attr('width', box_width)
         .attr('height', margin.bottom)
 
-    chart.set_yAxisTic( 0,  '0°')
-    chart.set_yAxisTic(26.6 * (Math.PI/180), '27°')
-    chart.set_yAxisTic(75 * (Math.PI/180), '75°')
-
     let sunData = []
     const year = data.beginTime.getFullYear()
     const month = data.beginTime.getMonth()
@@ -235,7 +231,7 @@ export function render_astronomy(canvas, width, height, offset, data) {
 
         // Solar Ephemeris
         let todaysSun = []
-        const sunEphem = SunCalc.getTimes(new Date(year, month, day, 1, 0, 0), lat, lon)
+        const sunEphem = SunCalc.getTimes(new Date(year, month, day, 2, 0, 0), lat, lon)
         todaysSun.push({
             'date': sunEphem.sunrise,
             'alt': 0
@@ -279,8 +275,10 @@ export function render_astronomy(canvas, width, height, offset, data) {
         .attr('class', 'sun')
         .attr('d', line)
 
-    // chart.draw_yAxisLine()
-    // chart.draw_xAxisLineTop()
+    chart.set_yAxisTic( 0,  '0°')
+    chart.set_yAxisTic(26.6 * (Math.PI/180), '27°')
+    chart.draw_xGrid(  26.6 * (Math.PI/180), 'guide')
+    chart.set_yAxisTic(75 * (Math.PI/180), '75°')
     chart.draw_xAxisLineBottom()
 }