\documentclass[9pt]{article}
\usepackage[utf8]{inputenc}
\usepackage[letterpaper, landscape, lmargin=0.25in, rmargin=1.25in]{geometry}
\usepackage{tabularx}
\usepackage{enumerate}
\usepackage{enumitem}
\usepackage{multicol}
\pagenumbering{gobble}
\title{5-Year Plan}
\author{author}
\date{}
\begin{document}
\maketitle
\begin{table}[h!]
\begin{center}
\begin{tabularx}{1.1\linewidth}{|l|X|X|X|X|X|X|X|X|X|X|X|X|}
\hline
&January&February&March&April&May&June&July&August & September & October &November &December \\ \hline
2020& &&&&&&&&&&& \\\hline
2021& &&&&&&&&&&& \\\hline
2022 & &&&&&&&&&&& \\\hline
2023& &&&&&&&&&&& \\\hline
2024& &&&&&&&&&&& \\\hline
2025& &&&&&&&&&&& \\\hline
\end{tabularx}
\end{center}
\end{table}
\end{document}
