How to convert the daily into half hourly

My date is from 01-01-1980 to 31-12-2015, the datenum is from 723181 to 736329, and i need to convert the daily time to half hourly. Hoe do I do ?

Thanks

Answer 1

[KSSV]

t0 = 723181 ;
t1=  736329 ;

t0 = [datestr(t0) ' 00:00:00'] ; 
t1 = [datestr(t1) ' 00:00:00'] ; 

t0 = datetime(t0) ; 
t1 = datetime(t1) ; 

thedates = (t0:hours(1/2):t1)' ;