Temporary Menu wide 10% price increase between specific hours

[LookoutTavernAZ]

Ok guys,  this is something that has plagued us for YEARS.  
We have many large, expensive events and I need to be able to boost either ALL prices, or prices of Alcohol or beer by say 10% for 3 hours, then return to the previous price.   HERE is the caveat.   Our liquor menu is using SIZE pricing,  with 6 size choices.  

The only way I see to boost prices is to expand every SINGLE category and increase by 10%   but then I have to RE-EDIT every single item again to change it back??!?!?   How can this not be resolved yet.  

We did a demo with another POS and they quickly had a tool,   select category,  select timeframe,  select price change,  up or down by percent,  or ADD a dollar amount.   Once the time is up,  it goes back.  

[www]

The only thing I can think of is creating another menu, and then using menu-specific pricing.

[Rob]

Thanks for reaching out to the Community! You could use time-specific pricing, but I'm not sure if that resolves adjusting each category. The instructions I found below, however, as www mentioned, it could be helpful to copy your current menu and create a "Events" menu that you could adjust pricing to more easily. 

1. Navigate to the group or item you would like to assign time-specific pricing to.
2. Select Time Specific Price for the Pricing Strategy setting.
3. Enter a Base Price.
4. A Time Prices table will appear in this section. Select + Add to create a window of time when the price should be changed. Choose the Time and Day settings to meet your needs.
5. Set the price increase by 10% for the desired time frame.
6. Repeat step 4 for any other time intervals when the price needs to be adjusted.
7. Save and publish your changes. This setup will automatically revert to the original pricing once the specified time frame ends.

Source:
Time-Specific Pricing |Set Your Menu Pricing Strategy
Reuse or Copy Menu Groups, Items, and Modifiers