Update about.md (#740)

Fix typos.

Author: hansonchar

concepts/date-time/about.md

@@ -3,7 +3,7 @@
 In Common Lisp time is represented in three ways
 
 - Universal time is an absolute time, an integer representing the number of seconds since `1900-01-01T00:00:00Z` (that is midnight on January 1st, 1900 in the UTC).
-- Decoded time is a tuple of 9 values, that together represent a specific calendar time: seconds, minutes, hour, day-of-month, year, day-of-week, DST flag, time zone.
+- Decoded time is a tuple of 9 values, that together represent a specific calendar time: seconds, minutes, hour, day-of-month, month, year, day-of-week, DST flag, time zone.
 (Discussed in detail below.)
 - Internal time is an positive integer in implementation defined 'internal time units' which can be used for measurements of run time.
 
@@ -27,7 +27,7 @@ A decoded time is a set of values:
 - *seconds*: an integer between 0 and 59
 - *minutes*: an integer between 0 and 59
 - *hour*: an integer between 0 and 23
-- *date*: an integer between 1 and 31 (upper limit actually depends upon month and year obviously)
+- *day of month*: an integer between 1 and 31 (upper limit actually depends upon month and year obviously)
 - *month*: an integer between 1 and 12
 - *year*: an integer indicating the year.
 - *day of week*: an integer between 0 and 6. 0 means Monday, 1 means Tuesday etc. ... 6 means Sunday.