Arithmetic 
Perform arithmetic datetime operations:
The add time and subtract
time operations
add or subtract the specified amount of time units (day, hour, millisecond, minute, second, or
week) to the original date and return a new date value.
The time after and time before operations measure the difference in the specified
amount of time units (day, hour, millisecond, minute, second, or
week) between the original date and the second date
and return a numeric value in time units.

Copy 
Copy into the specified
Result destination the desired extraction from datetime values
in the source field. Result types will automatically be
adjusted to either datetime or float64. Operations:
 date and time 
Copy into the specified datetime
Result destination the datetime values
in the source field.
 date without time 
Copy into the specified datetime
Result destination the datetime values
in the source field, setting all time portions of the data
time value to zero. For example, the date without
time result for 12/25/2016 13:43:53 would be 12/25/2016
0:00:00.
 day  Copy
into the specified numeric Result destination the day of the
month number of the datetime values in the source
field. For example, the day of the
month number for a datetime value of 12/25/2016
13:43:53 would be 25.
 hour  Copy
into the specified numeric Result destination the hour of
the day number, using 24 hour format, of the datetime
values in the source field. For example,
the hour of the day number for 12/25/2016 13:43:53 would be
13.
 millisecond 
Copy into the specified numeric Result destination the millisecond
number of the datetime values in the source field.
Many data sets do not bother recording greater
time detail than seconds, so the millisecond number of datetime
values is often zero.
 minute  Copy
into the specified numeric Result destination the minute of
the hour number of the datetime values in the
source field. For example, the minute
of the hour number for 12/25/2016 13:43:53 would be 43.
 month  Copy
into the specified numeric Result destination the month of
the year number of the datetime values in the
source field. For example, the month
of the year number for 12/25/2016 13:43:53 would be 12.
 second  Copy
into the specified numeric Result destination the second of
the minute number of the datetime values in the
source field. For example, the second
of the minute number for 12/25/2016 13:43:53 would be 53.
 week  Copy
into the specified numeric Result destination the computed
week of the year number of the datetime values
in the source field. Choosing the week
operator will open a Week
start parameter box allowing specification of the day
of the week (Sunday, Monday, Tuesday, Wednesday, Thursday,
Friday, or Saturday) on which a week is considered to begin.
Choosing a different Week
start day will often change the computed week of the
year. For example, 12/25/2016 13:43:53 falls on
a Sunday. The week of the year number for 12/25/2016
13:43:53 using a Week start
day of Sunday
would be 53. Using a Week start day of Monday
for that same datetime value would result in a week of the
year number of 52.
 week day 
Copy into the specified numeric Result destination the computed
day of the week number, from 1 to 7,
of the datetime values in the source field.
Choosing the week
day operator will open a Week
start parameter box allowing specification of the day
of the week (Sunday, Monday, Tuesday, Wednesday, Thursday,
Friday, or Saturday) on which a week is considered to begin.
Choosing a different Week
start day will often change the computed day of the
week number. For example, 12/25/2016 13:43:53 falls
on a Sunday. The day of the week number for 12/25/2016
13:43:53 using a Week start
day of Sunday
would be 1. Using a Week start day of Monday
for that same datetime value would result in a day of the
week number of 7.
 year  Copy
into the specified numeric Result destination the year number
of the datetime values in the source field. For
example, the year number for 12/25/2016 13:43:53 would be
2016.
 year day 
Copy into the specified numeric Result destination the computed
day of the year number, from 1 to 365,
of the datetime values in the source field. For
example, the day of the year number for 12/25/2016 13:43:53
would be 360.
