CALC: How to capitalize 3 letters of abbreviated month...?

hello.

i am trying to figure out how to format a date cell so that it will look like this:

30 OCT 2016

i understand the process of going to FORMAT/CELL/NUMBERS…etc. but so
far, i can only get this far with it:

30 Oct 2016

a small, if not trivial tweak, i admit but i am a ridiculous control freak when
it comes to my spreadsheet data! help!

I am a control freak probably more than you. But trying to get control on that level would require to establish a new feature concerning the ‘Numbers’ formats. Similar “feature enhancements” already complicated things to an extent that it gets more difficult to stay in control every other day.
Let us put the basic functionality into the focus. Silly smart features have already eroded necessary control in this range, too.

As long as your date is a formatted number (the default case) and not a text there is no way.
If you decide to convert the date into a text by a formula like =TEXT(NumericDateValue;"DD MMM YYYY") you can also use the UPPER function: =UPPER(=TEXT(NumericDateValue;"DD MMM YYYY")). Please consider the serious disadvantages of such decision.

(You should be very glad if you have not a more relevant problem.)

Doing as @karolus suggested without keeping a copy of the numeric dates will seriously complicate any calculations based on those dates (like “same day next week” e.g.). You should thoroughly consider related decisions.
(Also note: Despite the fact that the tool ‘Text’ > ‘UPPER-CASE’ is listed in the ‘Format’ menu, it does not change the format but the content.)

…… it doesn’t change anything unless the content is Text

Hallo

Unfortunatly you need to convert this Dates first into raw Text →select the Column[s] in question; goto→Data→Text to Columns→→no Delimiters! →select Columnheader in Preview and choose Text instead Default →→ok

Now go to →→Format→Text→UPPERCASE