Hi John,
Unfortunately, it gets a little ugly from here. :-)
To display month only, try this formula: valueexpression=IF(MONTH({entryDate})=1,"Jan", IF(MONTH({entryDate})=2,"Feb", IF(MONTH({entryDate})=3,"Mar", IF(MONTH({entryDate})=4,"Apr", IF(MONTH({entryDate})=5,"May", IF(MONTH({entryDate})=6,"Jun", IF(MONTH({entryDate})=7,"Jul", IF(MONTH({entryDate})=8,"Aug", IF(MONTH({entryDate})=9,"Sep", IF(MONTH({entryDate})=10,"Oct", IF(MONTH({entryDate})=11,"Nov", IF(MONTH({entryDate})=12,"Dec",""))))))))))))
Quarter only is a little less daunting, and this should work: valueexpression=IF(MONTH({entryDate})<=3,"Q1", IF(MONTH({entryDate})<=6,"Q2", IF(MONTH({entryDate})<=9,"Q3", IF(MONTH({entryDate})<=12,"Q4",""))))
As a side note, I have seen some weirdness where when you add a date field to a report using the field chooser, you may see something slightly different than when you put the date in a calculation. From what I can tell, this seems to be due to the “field chooser version” adjusting properly for your time zone, whereas the calculation does not. I only mention this because one of those was staring me in the face when I did a quick test before posting this! (e.g., my 3/31/2016 showed up as “Apr”)
Hopefully this gets you a little closer.
Kathy