You can adjust the `extradate` format:

```
\documentclass{article}

\usepackage[style=authoryear]{biblatex}

\begin{filecontents}[overwrite]{abcd.bib}
@article{test1,
  author={Niranjan},
  title={Article2},
  journaltitle={Journal},
  pages={1-5},
  date={2021-06-23},
  series={2},
  options={skipbib=true}
}
@article{test2,
  author={Niranjan},
  title={Article1},
  journaltitle={Journal},
  pages={6-10},
  date={2021-01-23},
  series={1},
}
\end{filecontents}
\addbibresource{abcd.bib}

\DeclareFieldFormat{extradate}{}

\begin{document}
See: \cite{test1}

See: \cite{test2}

\printbibliography

\fullcite{test1}
\end{document}
```

![Screen Shot 2021-06-23 at 14.54.49.png](/image?hash=d6b91570da745dcaa38feb9323c1819d1b1d05d739489d40c866c1ff1bba5432)