 date_time_value(?Key, 
+DateTime, ?Value)
date_time_value(?Key, 
+DateTime, ?Value)
| key | value | 
| year | Calendar year as an integer | 
| month | Calendar month as an integer 1..12 | 
| day | Calendar day as an integer 1..31 | 
| hour | Clock hour as an integer 0..23 | 
| minute | Clock minute as an integer 0..59 | 
| second | Clock second as a float 0.0..60.0 | 
| utc_offset | Offset to UTC in seconds (positive is west) | 
| time_zone | Name of timezone; fails if unknown | 
| daylight_saving | Bool (true) 
if dst is in effect | 
| date | Term date(Y,M,D) | 
| time | Term time(H,M,S) |