How do I implement a time picker?
Create a field , select field type as Date (ISO format) or Date. And choose only year, hour, minutes, seconds(if needed). Select Date entry options under MORE SETTINGS AND VALUES , choose custom format as H:i 

Add time format for H:i and also go-to admin/config/regional/date-time and add date type (to display in node view).
In add/edit page for time picker(only hours)



In view page



Hope this helps you with out any help of other modules.