Cumulative Sum irrespective of Time Range

Hi,

I have following scenario, where amount is credited every day and I would want to plot cumulative sum of amounts irrespective of time range.

For example,
1st Jan 2019 - Amount 50 is credited (Cumulative Sum - 50)
15th Jan 2019 - Amount 70 (Cumulative Sum - 120)
1st Feb 2019 - Amount 100 (Cumulative Sum - 220)
15th Feb 2019 - Amount 30 (Cumulative Sum - 250)
20th Feb 2019 - Amount 50 (Cumulative sum - 300)

I'm looking to plot a graph where x axis is date histogram and y axis is cumulative sum. When selected time range is for the month of feb (Feb 1st to Feb 20th), the graph is plotted with cumulative sum as 100,130 and 180 but I want the graph to be 220,250,300 (Including Jan amounts).

Any ideas on how to achieve it?