MRE:
% Preamble
\documentclass[11pt]{article}
% Packages
\usepackage[showdow,en-GB]{datetime2}
% Document
\begin{document}
% Turn off showdow
\DTMlangsetup{ord=raise,showyear=true,showdow=false}
% Format a date
\DTMdate{2019-01-01}
% Turn showdow back on
\DTMlangsetup{ord=raise,showyear=true,showdow=true}
% Format the same date
\DTMdate{2019-01-01}
\end{document}
Desired output:
1st January 2019
Tuesday 1st January 2019
Actual output:
Tuesday 1st January 2019
Tuesday 1st January 2019
Screnshot:
What am I doing wrong?