diff --git a/lightweight_charts/js/funcs.js b/lightweight_charts/js/funcs.js
index a0a3d0b..12c1917 100644
--- a/lightweight_charts/js/funcs.js
+++ b/lightweight_charts/js/funcs.js
@@ -404,7 +404,7 @@ function calculateTrendLine(startDate, startValue, endDate, endValue, chart, ray
     }
 
     if (startIndex === -1) {
-        return []
+        throw new Error(`Could not calculate start index from time ${stampToDate(startDate)}.`)
     }
     let endIndex
     if (ray) {
diff --git a/lightweight_charts/js/toolbox.js b/lightweight_charts/js/toolbox.js
index 2f3ff12..34bd86c 100644
--- a/lightweight_charts/js/toolbox.js
+++ b/lightweight_charts/js/toolbox.js
@@ -403,7 +403,6 @@ if (!window.ToolBox) {
         renderDrawings() {
             this.drawings.forEach((item) => {
                 if ('price' in item) return
-                console.log('rendering')
                 let startDate = Math.round(item.from[0]/this.chart.interval)*this.chart.interval
                 let endDate = Math.round(item.to[0]/this.chart.interval)*this.chart.interval
                 item.calculateAndSet(startDate, item.from[1], endDate, item.to[1])
@@ -453,8 +452,8 @@ if (!window.ToolBox) {
                         item.priceLine.lineStyle, item.priceLine.axisLabelVisible)
                 }
                 else {
-                    let startDate = Math.round(item.from[0]/this.chart.interval)*this.chart.interval
-                    let endDate = Math.round(item.to[0]/this.chart.interval)*this.chart.interval
+                    let startDate = Math.round((item.from[0]/this.chart.interval)*this.chart.interval)
+                    let endDate = Math.round((item.to[0]/this.chart.interval)*this.chart.interval)
 
                     drawing = new TrendLine(this.chart, item.color, item.ray)
                     drawing.calculateAndSet(startDate, item.from[1], endDate, item.to[1])