SQL - Get difference between two dates (by year/month/day)

select
trunc(months_between(fac_dte_final_mat+1,fac_dte_effective) /12) ||' Years '||
trunc(months_between(fac_dte_final_mat+1,fac_dte_effective)) ||' Months '||
trunc(fac_dte_final_mat+1-fac_dte_effective) || ' Days ' 
"Duration Pricing (fac)"
from 
vls_facility;