jQuery UI

jQuery UI (UserInterface) provides abstractions for low-level interaction and animation, advanced effects and high-level, themeable widgets, built on top of the jQuery JavaScript Library, that you can use to build highly interactive web applications.

Datepicker → The datepicker is tied to a standard form input field. Focus on the input (click, or use the tab key) to open an interactive calendar in a small overlay. Choose a date, click elsewhere on the page (blur the input), or hit the Esc key to close. If a date is chosen, feedback is shown as the input's value

• Datepicker examples
• Have a look too: Date Picker

jQuery Datepicker and Timepicker for same input field to popup one after another

UiTimepickr → jquery.timepickr was created in a attempt to make the process of inputing time in a form as easy an natural as posssible.

• Demo

New DateTimePicker features & new stand-alone Timepicker (Martin Milesich)

• Demo
• A Timepicker for jQuery-UI → I'm working with people who have a need for such a control and who thought his would suffice. But I think the sliding controls are non-obvious for users. With five minute intervals satisfactory to the task at hand I redesigned the plugin.

Date-Time-Picker with jQuery UI Datepicker *

• did preliminary work on the timepicker component alone

Date Range Picker using jQuery UI 1.7 and jQuery UI CSS Framework