Allow two digits for BYDAY

[tchandelle]

Fixes #176

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[codecov-io]

Codecov Report

Merging #330 into master will increase coverage by 0.1%.
The diff coverage is 100%.

@@            Coverage Diff            @@
##           master     #330     +/-   ##
=========================================
+ Coverage   89.88%   89.98%   +0.1%     
=========================================
  Files          28       28             
  Lines        1947     1947             
  Branches      581      581             
=========================================
+ Hits         1750     1752      +2     
+ Misses        197      195      -2

Impacted Files	Coverage Δ
src/parsestring.ts	94.84% <100%> (ø)	⬆️
src/nlp/parsetext.ts	53.63% <0%> (+0.69%)	⬆️

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