convert Mysql week to Date using Date.commercial - mysql

Question

After Fetching objects form database
Object.select('week(created_at) as week, year(created_at) as year')
which returns week from 0 to 53 then creating a Date object from it
Date.commercial(x.year,x.week,1)
It reporting 'invalid date' error due to 0 and 53 no of week.
I have also tried this one.
Date.strptime("#{x.year}-#{x.week+1}-1","%Y-%W-%w")
But it also crashing due to x.week+1 (e.g. 53+1). Searching one line solution

Answer 1

I think your usage is wrong
I found this below from (here).
To be sure, please send your ruby version and also your x.year and x.week output.
commercial(y=-4712, w=1, d=1, sg=ITALY) click to toggle source
Create a new Date object for the Commercial Date specified by year y, week-of-year w, and day-of-week d.
Monday is day-of-week 1; Sunday is day-of-week 7.
w and d can be negative, in which case they count backwards from the end of the year and the end of the week respectively. No wraparound is performed, however, and invalid values cause an ArgumentError to be raised.
y defaults to -4712, w to 1, and d to 1; this is Julian Day Number day 0.
sg specifies the Day of Calendar Reform.emphasized text

Answer 2

Don't add 1 to x.week in your strptime.

Answer 3

You should fetch the date from DB in an ISO 8601 format.
This format returns weeks from 1 to 52, that complies with the input that #commercial expects.
In Ruby:
ISO 8601 week-based year and week number:
The week 1 of YYYY starts with a Monday and includes YYYY-01-04.
The days in the year before the first week are in the last week of
the previous year.
%G - The week-based year
%g - The last 2 digits of the week-based year (00..99)
%V - Week number of the week-based year (01..53)
from https://ruby-doc.org/stdlib-2.5.1/libdoc/date/rdoc/Date.html#method-i-strftime
In MySQL:
%V Week (01..53), where Sunday is the first day of the week; WEEK() mode 2; used with %X
%v Week (01..53), where Monday is the first day of the week; WEEK() mode 3; used with %x
%X Year for the week where Sunday is the first day of the week, numeric, four digits; used with %V
%x Year for the week, where Monday is the first day of the week, numeric, four digits; used with %v
SELECT DATE_FORMAT('1999-01-01', '%X %V');
+------------------------------------+
| DATE_FORMAT('1999-01-01', '%X %V') |
+------------------------------------+
| 1998 52 |
+------------------------------------+
from https://dev.mysql.com/doc/refman/5.6/en/date-and-time-functions.html#function_date-format