Problem summary

The user wants to find or submit information based on a date or date range.

Solution

The calendar picker is activated in a variety of ways:

• When clicking a link prompting for selecting a date
• When selecting an field for inputting a date
• When clicking a calendar icon most often placed next to the field used for inputting a date

On activation, a box with a month-calendar is displayed on the current page, prompting the user to select a date in the box. It is most common to only show one month, but some interfaces show up to 3 month calendars next to each other to ease the click-burden of the user and provide a better overview.

Shortcuts

The month-box calendar comes with several different shortcuts:

• Select a date
• Go to the previous/next month
• Go to the previous/next year
• Go to today (Especially important when today’s date is not the default)
• Close the calendar picker

Locking-in the period of selection

For some interfaces, it makes sense to not allow the selection of certain dates. An example often used is to only make it possible to select banking days, days in the future, or days within the few forthcoming months.

Two ways of inputting data: speedy and easy

When designing for efficiency in web application, an area that often gets little attention is the contexts of input. On most desktop computers the most common way of inputting data is via keyboard or mouse. On mobile devices touch, keyboard and camera are the most common input methods.

Using a calendar picker is an easy way of inputting a date. But also consider a quick and effortless way to input a date – one were the user does not need to switch between input devices but can rather accomplish their task with a single input device.

For accommodating text inputs, consider using the Forgiving Format pattern to lessen input errors.

Good defaults

Use the Good defaults pattern to achiee better data and spelling accuracy on input by pre-selecting appropriate dates.

The defaults you pre-select will depend on the context but will most often be the current date or time. However, If you were designing a public transport route planner, you might default the start time to a half hour from now, as most travellers won’t be starting their journey right away when searching for a fare.

Check date range validity

If the user is selecting a date range, it is good practice to never let end-date be before the start date. That means listening to the start-date for changes and changing the end-date if the start date is set to anything bigger.

Display complete weeks

Display complete weeks, even when a month does not begin at the end of the week. Grey out visible dates from previous and next months, but be sure they are still selectable.

Make link targets big

Make sure that link targets are big and thus easy to click on.

Rationale

The calendar picker is a familiar graphical interface that is commonly understood among users. It helps the user easily choose a date or date range for use in submitting information or filtering data.