The diurnal will
always be exactly like the natal (birth info-wise),
except for the date.
If the Natal is CST, the diurnal should be CST too.
If you're in an animated Bi-Wheel (Transits) for instance and are ready to check diurnal positions, if you put in the birthdate, the two charts should be identical. If so, then, just changing the date, will give you the diurnal for any date. I do it this way, since I am normally looking at quite a few different dates for various events. This way, I'm not cluttering up with tons of charts, rather seeing them each in the animated Bi-Wheel, as I'm analyzing them.
If you want to have the charts on-hand, then create the individual charts...
When I ask for a diurnal chart (from Janus 5.5), I get the following...where ONLY the date can be changed...because that's how it's done.