To choose date at expense entry screen.
Do we need to show next/previous month date in current month date? It can be useful for end of the month. But for other days? I think it looks cluttered with others, even with color variations.
Please share your thought on this.
People operate on dates in variety of ways:
As you see, relative way is often prevalent. Calendar with next/previous dates extends the context of use and support relative date references and natural dates flow.
Finally, calendar is just a convention in days labeling. Natural dates flow is sequence, so Jan, 1 after Dec, 31 is not great break, it's just a next day.
As you can see, the calendar control in your example uses a 6-week format. A 31-day month with two days or less in one calendar week will have at least one day in each of six calendar weeks (four "complete" weeks, two days in a fifth week and one day in the sixth). So, your calendar must be able to show that many weeks in order to be able to show every possible permutation of days in a month.
Given that requirement, showing extra days or even full weeks not belonging to the month in a control like this has a few advantages:
The control can be statically sized, regardless of the month/year being shown, or the user's preference for first and last days of the week. This makes your overall layout much easier to plan; nothing will have to be resized dynamically to account for the size of the control.
Even if you're showing a month like February 2009 (which started on a Sunday and ended on a Saturday), it would only span four weeks on an "Abrahamic" calendar layout, in which the first day is Sunday. Using a "business" layout (first day is Monday), Feb 2009 would span five weeks, and Feb 2010 would be the four-week permutation, so your control would be sized differently for different users viewing the same month.
It makes good use of otherwise wasted whitespace. Given that you need space for 6 weeks, why not show the full six weeks? It reduces the number of clicks required, for instance, to select September 6th in the calendar when you're looking at August, rather than having to advance the month to select a day in that month.
It allows people to work with your control in terms of weeks as well as months. As Alexey pointed out, the extra selectable days allows you to think in terms of complete weeks, whether the week you're interested in is the current one, or a past or future one.
I have written a blog post some time ago about pagination, which covers the calendar example as well: https://medium.com/because-we-love-software/b982fff3626c.
From my point of view, one should not restrict the user to only see the current month, as it just prevents further information. So in the case of a calendar, why only show months? I would suggest to show the current date and the upcoming weeks. Of course if your application depends on dates in the past, then you could show him the relevant amount of weeks that are over.
