Worksheet Font Change in Calc - impossible task?

I’ve been trying to change the global font size in Calc for an entire template. After looking up directions in this forum, i’v gone thru the Styles>Default>Modify Styles>Font tab process to try to change the font size for the whole worksheet. For some reason, it’ll change the font size for only two rows, not the whole sheet. Also, when i try to change the default number and time format, those changes won’t save… what the hell is going on? I’ve been at this way too long…

you should change font in style and then apply that style to all needed CELLS on your sheet. because Calc has CELL style.

Changing font in default style should apply to the whole sheet, except other styles that don’t heritage from default are being applied in some cells or some direct formats.

Also, when i try to change the default number and time format, those changes won’t save…

You cannot change that - the defaults (in the Default cell style) are specific to your language setting. If you want to use your own e.g. number format, you need to define a new cell style configured with the desired number format and you need to apply that cell style to the cells requiring this format.