Date issue for month having 31 days

### I'm Submitting a ...

```
[x] Bug report
[ ] Feature request
[ ] Support request
```

### Steps to Reproduce

1. On September 2020 month window select 31 Aug
2. Date entered in text box is 1st August 2020.
3. Same is happening for 31 Jan, 31 Mar, 31 May.

### Expected Results

Expected date should be the one which is selected.

### Actual Results

This is occurring for months having 31 days, except July.

### Minimal Reproduction of the Problem

### Other Information (e.g. stacktraces, related issues, suggestions how to fix)