meetup: sync (#728)

exercises/practice/meetup/.docs/instructions.md

@@ -1,27 +1,34 @@
 # Instructions
 
-Calculate the date of meetups.
+Your task is to find the exact date of a meetup, given a month, year, weekday and week.
 
-Typically meetups happen on the same day of the week.  In this exercise, you
-will take a description of a meetup date, and return the actual meetup date.
+There are five week values to consider: `first`, `second`, `third`, `fourth`, `last`, `teenth`.
 
-Examples of general descriptions are:
+For example, you might be asked to find the date for the meetup on the first Monday in January 2018 (January 1, 2018).
 
-- The first Monday of January 2017
-- The third Tuesday of January 2017
-- The wednesteenth of January 2017
-- The last Thursday of January 2017
+Similarly, you might be asked to find:
 
-The descriptors you are expected to parse are:
-first, second, third, fourth, fifth, last, monteenth, tuesteenth, wednesteenth,
-thursteenth, friteenth, saturteenth, sunteenth
+- the third Tuesday of August 2019 (August 20, 2019)
+- the teenth Wednesday of May 2020 (May 13, 2020)
+- the fourth Sunday of July 2021 (July 25, 2021)
+- the last Thursday of November 2022 (November 24, 2022)
+- the teenth Saturday of August 1953 (August 15, 1953)
 
-Note that "monteenth", "tuesteenth", etc are all made up words. There was a
-meetup whose members realized that there are exactly 7 numbered days in a month
-that end in '-teenth'. Therefore, one is guaranteed that each day of the week
-(Monday, Tuesday, ...) will have exactly one date that is named with '-teenth'
-in every month.
+## Teenth
 
-Given examples of a meetup dates, each containing a month, day, year, and
-descriptor calculate the date of the actual meetup.  For example, if given
-"The first Monday of January 2017", the correct meetup date is 2017/1/2.
+The teenth week refers to the seven days in a month that end in '-teenth' (13th, 14th, 15th, 16th, 17th, 18th and 19th).
+
+If asked to find the teenth Saturday of August, 1953, we check its calendar:
+
+```plaintext
+    August 1953
+Su Mo Tu We Th Fr Sa
+                   1
+ 2  3  4  5  6  7  8
+ 9 10 11 12 13 14 15
+16 17 18 19 20 21 22
+23 24 25 26 27 28 29
+30 31
+```
+
+From this we find that the teenth Saturday is August 15, 1953.

exercises/practice/meetup/.docs/introduction.md

@@ -0,0 +1,29 @@
+# Introduction
+
+Every month, your partner meets up with their best friend.
+Both of them have very busy schedules, making it challenging to find a suitable date!
+Given your own busy schedule, your partner always double-checks potential meetup dates with you:
+
+- "Can I meet up on the first Friday of next month?"
+- "What about the third Wednesday?"
+- "Maybe the last Sunday?"
+
+In this month's call, your partner asked you this question:
+
+- "I'd like to meet up on the teenth Thursday; is that okay?"
+
+Confused, you ask what a "teenth" day is.
+Your partner explains that a teenth day, a concept they made up, refers to the days in a month that end in '-teenth':
+
+- 13th (thirteenth)
+- 14th (fourteenth)
+- 15th (fifteenth)
+- 16th (sixteenth)
+- 17th (seventeenth)
+- 18th (eighteenth)
+- 19th (nineteenth)
+
+As there are also seven weekdays, it is guaranteed that each day of the week has _exactly one_ teenth day each month.
+
+Now that you understand the concept of a teenth day, you check your calendar.
+You don't have anything planned on the teenth Thursday, so you happily confirm the date with your partner.

exercises/practice/meetup/.meta/config.json

@@ -20,6 +20,5 @@
     ]
   },
   "blurb": "Calculate the date of meetups.",
-  "source": "Jeremy Hinegardner mentioned a Boulder meetup that happens on the Wednesteenth of every month",
-  "source_url": "https://twitter.com/copiousfreetime"
+  "source": "Jeremy Hinegardner mentioned a Boulder meetup that happens on the Wednesteenth of every month"
 }