Challenge #486: Prepare for Your Assignment Reviews!

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Hi Community members,

A solution to last week’s challenge can be found here.

This challenge was submitted by Jifeng Qiu (@Qiu) , and inspired by a Community discussion started by @taschmies. We appreciate you both for bringing this case forward!

You have a series of assignment reviews scheduled for 2025/26. These reviews are important and it takes you at least two full working days to prepare for each of them. In some cases, multiple reviews may be scheduled on the same day and you must account for that in your preparation time.

Naturally, you won’t be working on weekends or public holidays. Based on the Review Schedule and the List of Holidays for 2025/2026, calculate your preparation days and mark them on the calendar:

PrepDate1 = Review Date − 2 working days
PrepDate2 = Review Date − 1 working day

Hint: Make sure to update the column names in your input files.

Once you have completed your challenge, include your solution file and a screenshot of your workflow as attachments to your comment.

Good Luck!

The Academy Team

Source: https://community.alteryx.com/t5/Alteryx-Designer-Desktop-Discussions/Work-backwards-from-a-given-date-to-return-two-workdays-prior/m-p/1392951

Challenge 486_solution_file.yxzp

Challenge 486_start_file.yxzp

Data Preparation

Core

Basic

Accepted answers

All comments

alexnajm

Done, although my output is different than the provided. I feel like I read the instructions correctly so I am happy with my answer but happy to see what others come up with

Spoiler

For the first record of 2025-10-03, shouldn't the answer be 2025-10-01 and 2025-10-02 since there are no holidays / weekends?

also the record 2025-12-02 has the same date as the prep dates...
challenge 486.png

Challenge 486_start_file_alex Abi-Najm.yxzp

abacon

I also got a different answer, but I feel good about it as well.

Spoiler

Challenge 486_abacon.yxmd

jeprime

Spoiler

Not sure how the Output Solution applies. Many of the answers show that both PrepDate1 and PrepDate2 are the same date (logically incorrect). However, I chose the easier path and did not seek an answer that the challenge requested - each "Prep Day" is a "Full Day", which meant that none of the other "Prep Days" can conflict. This poses a difficult challenge I chose to not partake in. Like those answering before me, I chose to simply find the two days before the review date that weren't weekends or holidays, only.

Food for thought - how DID the solution table get created?

JEP_Challenge 486_solution.yxmd

Pilsner

Interesting challenge! Ended up approaching it from multiple angles. I didnt quite get my answer to match but Im guessing thats down to my interprestation of the question.

Spoiler

I took 3 seperate approaches, heres a brief breakdown of the thought preocess behind each method:

1) At first, I assumed no overlap was allowed, i.e if there were 3 reviews due on the same day, the preparation would need to start 6 days prior to the review date (2 days per review). However, this lead to a backlog of preparation days from 2024 so realised this was likely incorrect.

2) My next solution assumed that overlap was allowed therefore you could prep for more than one review on a given day. This solution thankfully didnt require an itterative macro but was still fun to build.

3) My final solution was a combination of the previous ideas. Only reviews happeing on the same day, could also be prepared for on the same day. All other revies had to have seperate designated preparation days.

Although my answer still didnt match I think I was along the right lines, plus there is always a chance I made a mistake early on, throwing all my solutions off. This challenge certianly made me think!

Workflow:

Macro:

486 (Preparation Days).yxzp

jeprime

Like you, I decided to only find days that weren't holidays or weekends, barring determining if any prep-days overlapped with other prep-days. Still curious how they derived that solution.

Erin

Like others, I have different answers than the posted output. But.....IDK it makes sense to me. 🤓

Spoiler

challenge_486_submission_EM.yxzp

jrlindem

Oof, this one was a bugger.

I, like others, found the solution to be problematic. I kind of ran into the same issue as the provided example solution where after a few rows the -1 and -2 dates weren't operating correctly. I found, in my case, that when there were repeated ReviewDates in a row, the multi-row formula, if not configured well, was reading preceding dates of the exact same date in the span. This is solvable (as seen in my example) but I admit that I did this in a down-and-dirty sort of way. Not ideally how "clean" I typically like my workflows to operate.

Regarding what I believe the "spirit of the challenge" to be... I liked others observations that this sounded more like an iterative macro challenge where maybe there is a maximum capacity for preparation days and that needed to be removed out when there were multiple reviews needed on the same day. That said... I did not build my solution to solve for this. I simply provided the preceding two days (Skipping Non-Work Days or Weekends).

Here's my solution:

Spoiler

Challenge+486_jrlindem_solution.yxzp

lwolfie

I came close to the output. However, I couldn't quite figure out what the logic was for the multiple reviews due on the same day. I had 13 days that didn't match.

Challenge 486_solution_LW.yxzp

Qiu

@alexnajm @abacon @jeprime @Pilsner @jeprime @Erin @jrlindem @lwolfie
Thank all very much for your insights.
I guess there was some mistake in my original solution in the original post.
I will take a close look by comparing mine with yours and hope find the most logical one.
https://community.alteryx.com/t5/Alteryx-Designer-Desktop-Discussions/Work-backwards-from-a-given-date-to-return-two-workdays-prior/td-p/1392951

As @jrlindem interestingly pointed out, in the "spirit of the challenge", the more we discuss on the topic, which is one "close" to real bussiness problem, the more we can understand and learn, at least for me.

Thank you all again. 😁

Ps: @AYXAcademy Thank you for accepting my weekly challenge idea.

Yoshiro_Fujimori

My solution.

Did not match the expected output, same as my friends.

Spoiler

Workflow
Challenge+486_workflow.png

Output

ReviewDate	PrepDate1	PrepDate2
2025-10-03	2025-10-01	2025-10-02
2025-10-08	2025-10-06	2025-10-07
2025-10-16	2025-10-14	2025-10-15
2025-10-17	2025-10-15	2025-10-16
2025-10-25	2025-10-22	2025-10-23
...

Challenge 486_YFujimori.yxzp

carloslmg

First time doing one of these. I think I got a different approach from other members here.

Spoiler

Challenge+486_submission.yxzp

alineruizcampos

I solved this in two different ways:

Ignoring the fact that the reviews take two full working days and allowing multiple assignments to be reviewed per day (as others have done)
Allowing only one assignment to be reviewed per day (using an iterative macro)

For option 2, the first PrepDate I got goes back to May 2024 and therefore we would need a 2024 holiday schedule. Anyway, seems silly to be reviewing an assignment with review date of October 2025 in May 2024 so maybe I misunderstood the question.

Spoiler

Challenge 486_Aline.yxzp

AkimasaKajitani

My solutuion.

My approach is to create the calender that has previous working days and then join those data. So, the result is not the same.

Spoiler

Challenge 486_start_file_AK.yxzp

Bobbyt23

@Qiu Just checked out your response to that question and the only difference I can see is when you sort after the output of the first Join. It is Review Date ascending and Row Count ascending, you then sample top 2. I think it needs to sample bottom to if you sort that way, or if you want Top 2 it would need to be Row Count Descending. Really fun challenge though!

Bobbyt23

A nice challenge with lots of fun tools to use.

Spoiler

Weekly Challenge 486 14-08-25.yxzp

Krzysiek

MySolution

Challenge 486_mysolution.yxmd

RWvanLeeuwen

So I interpreted the challenge as follows: Create a schedule that allows you to prepare for the reviews on time. You'll need two days to prepare, and you cannot prepare multiple reviews on the same days. Therefor you must create a schedule that allots two workable preparation days for each planned review.

So have a look at what I built:

Spoiler

Challenge 486_start_file - RWvL.yxmd

RWvanLeeuwen

Of note: my solution does not take into account that the preparation dates are before the scheduled review date, but I did not fix this problem because the overall preparation schedule is ONE YEAR BEHIND approximately😆

balajilolla3

Spoiler

Solution Attached

Solution Screenshot.png

Challenge 486_start_file.yxmd

JBevan89

Spoiler

Like others, the Solution is not right because for one reason it has Non-Working days as the Prep Days.

Otherwise, i'm happy with my workflow and the way I attempted this. I really like to use the 'Generate Rows' tool with challenges like this, because what it does is create a list of dates for each review date, so effectively creating sub-rows for the rows. And then the beauty is that you then have more data to analyse and then narrow down to the correct result you are looking for.

Challenge 486_JB.yxmd

rmassambane

486

Challenge 486_start_file.yxmd

olga_strubbe

Thank you, @Qiu.

I renamed the column headers in my Input configuration - saved a couple extra tools

I also noticed some inconsistencies as the other members of the community pointed out. I think the task can be interpreted in different ways which can result in different solutions. For example, if the reviews are on the same day, and since it takes at least 2 days to prepare for each review, they all need to be spaced out to prepare for. Or is it that all of that day's reviews take at least 2 days to get ready for? The latter is the logic I adhered to. My solution jives with the approach @Erin applied.

I noticed inconsistencies in the solution output provided as well - see a screenshot below: The PrepDate1 needs to be 2 work days prior to review while PrepDate2 needs to be 1 work day prior to review date; however in the solution output provided PrepDate2 is the same as PrepDate1 for quite a number of reviews, and in some cases PrepDate2 comes before PrepDate1 which defies the task set forth.

Here is my solution, it is attached here as well.

Spoiler

And here is an extract from the solution output provided to this challenge which illustrates the inconsistencies I pointed above.

The 2nd column is PrepDate1 and last column is PrepDate2.

Spoiler

Good challenge, but I think some clarity, setting the framework for the task, and the output that jibes with the task set forth would be helpful here. Thank you.

Challenge 486_OS.yxmd

olga_strubbe

I meant to say 'My solution jibes with the approach @Erin applied.' Sorry for the typo

Hub119

Started going down many rabbit holes of building various iterative macros (too much AoC lately I guess 🤣) to ensure that prep dates were uniquely used and did not overlap with existing review dates, thinking only one task could be done on a given day... but then decided if multiple reviews were on the same date, why should I worry about that? I did at least construct this so if 10 reviews were on a given day the prep days were split up amongst the previous 20 available...

Spoiler

Challenge 486 - CH Solved.yxzp

Qiu

@Hub119
Thank you for jumping in also.

RolandSchubert

Spoiler

Challenge 486_solution_rsc.yxzp

Kenda

Spoiler

my take...

Challenge 486_start_file.yxmd

mmontgomery

c486

Spoiler

c486.yxzp

DaisukeTsuchiya

I couldn't get the same answer.

Spoiler

Challenge 486_start_file_DT.yxzp

JulianHalseyMilhaupt

I assumed the student could not have a prep day on a review day and that they could not prep for two reviews in the same day.

Spoiler

Challenge 486_JHM.yxmd

clewis28

Spoiler

Challenge 486_clewis28.yxmd

Reesetrain2

All,

My solution!

Spoiler

Challenge+486_Reesetrain2.yxzp

barrymoe

almost impossible!

Challenge+486_start_file.yxzp

wbasuki

I see that there are some 'non working day' under preparation day in the output table, therefore I change my goal to match with the output table and not consider 'non working day' in the workflow, and here it is.

Spoiler

Challenge 486_start_file_WB.yxzp

RebekaMazuchova

I wouldn't consider this one Basic/Core, as I believe it requires the use of an iterative macro.

Btw, we should have started the preparations in March 2024.

Challenge 486_RM.yxzp

Harley123

Hey @alexnajm I feel like your approach and output make more sense to me. Appreciated it!

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