lib/roi/rentability.rb in roi_calculator-0.1.3 vs lib/roi/rentability.rb in roi_calculator-0.1.4

@@ -62,10 +62,10 @@
 
       0.upto(filtered.size - days).map do |low|
         series = filtered.slice(low, days + 1)
         vol = MathUtil.volatility(series)
         date = dates_with_position.fetch(low + days) { dates_with_position.last }
-        [date.to_s(:db), vol] if date
+        [date.strftime("%Y-%m-%d"), vol] if date
       end
     end
 
     def to_a
       dates_with_position.map do |date|