Version 2018.02 improves the usability of the date and time pickers by showing the currently specified date or time range when editing the start or end date/time of an event or task. The highlighting makes it easier to see the current date/time range when deciding on a different value.
In the example below, an event starts at 8:00 AM and ends at 10:30 AM. When the drop-down is clicked for the "End time" field, we can see the current time range is highlighted blue, and the selected value is in bold.
In another example, we can see the currently specified date range is highlighted when the "End date" drop-down is opened. Since dates can also be highlighted with colors of events or tasks, the current date range is also made bold.