I was not able to shift the dates to downward position here is my MWE
\documentclass[a4paper,landscape]{article}
\usepackage[left=1cm,bottom=2cm,top=2cm,right=1cm]{geometry}
\usepackage[utf8]{inputenc}
%%in preamble:
%
\usepackage{tikz}
\usetikzlibrary{positioning,calendar}
\usetikzlibrary{decorations.markings}
\newcommand{\calrow}[1]{\node[anchor=base east,xshift=1em,yshift=-11.5em](Mon){\rotatebox{0} {\color{blue}Urmi}};
\node[base right=of Mon,xshift=0.5em](Tue){\rotatebox{0}{\color{blue}Durmi}}; \node[base right=of Tue](Wed){\color{blue}Thelang};
\node[base right=of Wed](Thu){\color{blue}Theman}; \node[base right=of Thu](Fri){\color{blue}Bhomta};
\node[base right=of Fri](Sat){\color{blue}Bhomti}; \node[base right=of Sat](Sun){\color{red}Bhomkuru};
\node[darkgreen,above=of Thu]{\textbf{#1}};
\node[darkgreen,above=of Sun]{\textbf{\the\year}};}
\newcommand{\calperiod}[1]{\calendar[dates=\the\year-#1-01 to \the\year-#1-last]
if(Sunday) [red] \holidays;}
\newcommand{\holidays}{% holidays in Italy
if (equals=01-01) [black!50]%
if (equals=01-06) [black!50]%
if (equals=04-04) [black!50]%
if (equals=04-05) [black!50]%
if (equals=04-25) [black!50]%
if (equals=05-01) [black!50]%
if (equals=05-01) [black!50]%
if (equals=06-02) [black!50]%
if (equals=08-15) [black!50]%
if (equals=11-01) [black!50]%
if (equals=12-08) [black!50]%
if (equals=12-25) [black!50]%
if (equals=12-26) [black!50]%
}
\pagenumbering{gobble}
\usepackage{graphicx}
\colorlet{darkgreen}{green!0!black}
\year=2017
\begin{document}
\begin{tikzpicture}[every calendar/.style={week list},day xshift=4em,yshift=-24cm,darkgreen,node distance=0.1ex]
\sffamily
\node at (12.50,0.90) {\includegraphics[width=15cm,height=5cm]{img/31.jpg}};\\
\hspace*{60mm}\LARGE{\scalebox{1.0}{\calrow{\color{blue}Arkoi({\it January})} \\
\calperiod{01}
}};
\end{tikzpicture}
\end{document}
I need dates to print below the row contains Urmi, Durmi...Bhomkuru


(12.50,3.90)and let us know whether it works. It works for the MWE that you posted, at least for me. If there are other constraints, update your MWE with relevant information – Troy May 28 '17 at 03:09\calendar at (x,y) [...options...]. – Troy May 28 '17 at 03:25