Click on ribbon tab Edit in group Insert on the item Insert template for opening the pop-up menu and click on first item Modify templates.

Template group is Global. Click on button + and type the name for the template like Time or Current time and next define the template content for inserting the current time in the format you want.
Click on button Help to get opened the help page Modify templates command (Edit tab/Insert template dropdown) explaining the placeholders which can be used for a smart template.
Example: The current local time could be inserted with: [TIME_USER]HH':'mm':'ss[TIME_USER_END]
Also enter a useful description like: Insert current local time in 24-hour format
Click the button OK.

There is by default enabled at Advanced - Settings or Configuration - Templates the configuration setting Auto-suggest smart template when typing. If you type the beginning of the name you gave the template like time or curr a pop-up window appears suggesting inserting the smart template. Press key TAB or RETURN or ENTER to insert the smart template resulting in inserting the current time in the format as defined by you.

There can be opened also  Advanced - Settings or Configuration - Key mapping, scrolled in the list of commands to User template 0 if that smart template is the first global template, and assign a hotkey or chord of your choice to this command for inserting the smart template (=current time) by pressing the configured combination of keys.

Global templates like this one can be inserted also using a macro or a script by the appropriate macro/scripting command with the name of the template.

Last but not least the smart template can be inserted also with a double click on it in the Template List view of which visibility can be toggled with a click on check box item Templates on the ribbon tab Layout if not being configured to be always visible docked on left or right side with auto-hide feature enabled to increase horizontal space for the document windows on not being currently needed.