Time restricted access to check-out (or component)

-- HikaShop version -- : 2.6.4
-- Joomla version -- : 3.6.2
-- PHP version -- : 7.0.6
-- Browser(s) name and version -- : na
-- Error-message(debug-mod must be tuned on) -- : none

Is there any way to automatically make checkout not possible (or the entire store offline) for certain times each week?

We would like to have the store be not accessible during a certain period of time each week, and we need to automate the process.

I have not found a way to do this within Hikashop itself; however I may have missed something.

I've looked for other HS extensions but didn't find anything like this.
If it isn't possible with core HS setttings, is there a way to do this through a work-around?
(Or possibly just a custom php script that runs by cron to set the 'Put the store offline" to YES (and then back to NO at a certain time? Is that field easily accessible somewhere to set externally?)

Thanks. However, what I specifically need is the ability to JUST close the store on Mondays from 15:00 - 20:00. We need to have it open all other days 24/7.

Can I programattically (via cron) just change those hours on Monday and then reset them on Tuesday each week?

Although I'd love to help support Polished Geek, this project is for a small non-profit so can't afford outside plugins.

So the view override will be a good option for us.

Do you have any documentation about how to properly add PHP code to a view override for something like this (or ANY samples of PHP functionality within a view override would be helpful).
Also, do you have a list of what variables/data are available within different view files?

I've done only a few view overrides, so I'm not all that experienced with that.

Thanks for the reference to the checkout/ste.php file. Exactly what I needed for this.

However, I wasn't clear about the variables.
Can I use normal Joomla! JFactory::getUser() (and other Joomla functions) within this file?