Weekday and Time function - forum topic by dmenzaghi

Hi all,
i'm new in this forum.
I have to simple problems that i cannot solve:
- I need to find a function that calculate in Teradata the weekday of a date variabile.
- i need to compare a Time variable whit some constant values:
 ie.  
  case
     when  var_time < '18:00' then 1
     when  var_time < '11:00' then 2
 
Thanks in advance for you help
D.