Date function:
<=                 
- CURRENT_DATE     
- CURRENT_TIME     
- CURRENT_TIMESTAMP
- DATE             
- DATEDIFF         
- DATE_ADD         
- DATE_SUBTRACT    
- DAY              
- DAYNAME          
- DAYOFWEEK        
- DAYOFYEAR        
- EXTRACT          
- LAST_DAY         
- MONTH            
- MONTHNAME        
- QUARTER          
- TIME             
- TIMEDIFF         
- TIMESTAMPDIFF    
- WEEK             
- WEEKDAY          
- YEAR