Historical calendar dates: days were skipped in Finland in February 1753

Real result:

$ LC_ALL=fi_FI.utf8 cal feb 1753
   Helmikuu 1753
su ma ti ke to pe la
             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

Expected result:

$ LC_ALL=fi_FI.utf8 cal feb 1753
   Helmikuu 1753
su ma ti ke to pe la
             1 2 3
 4 5 6 7 8 9 10
11 12 13 14 15 16 17

Background:

The days 18-28 (inclusive) were dropped in February 1753 to skip from Julian calendar to Gregorian calendar. Scanned image of the original calendar can be found at https://almanakka.helsinki.fi/images/arkisto/1700/175302.gif and all calendars between 1700-1799 can be found at https://almanakka.helsinki.fi/fi/arkisto/yliopiston-almanakat-universitetets-almanackor-1608-1999/1700-luvun-almanakat.html

This change is similar to British calendar in September 1752.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: language-pack-fi 1:16.04+20160627
ProcVersionSignature: Ubuntu 4.4.0-24.43-lowlatency 4.4.10
Uname: Linux 4.4.0-24-lowlatency x86_64
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
CurrentDesktop: X-Cinnamon
Date: Mon Aug 15 18:02:39 2016
InstallationDate: Installed on 2015-02-23 (539 days ago)
InstallationMedia: Ubuntu 14.04.2 LTS "Trusty Tahr" - Release amd64 (20150218.1)
PackageArchitecture: all
SourcePackage: language-pack-fi
UpgradeStatus: Upgraded to xenial on 2016-06-10 (66 days ago)