CreationTime, what to use, int, float, if I want to write it in another method?

When sharing code, put it in code tags:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using TMPro;
using System.IO;
using System.Linq;
public class FileCreatorLinks : MonoBehaviour
{
    public Transform Template;
    public Transform Parent;
    public Image SplitImage;
    public void Start(int positionIndex, PDFExtraction pdfExtraction, Sprites sprites)
    {
        DirectoryInfo directory = new DirectoryInfo("Assets/Resources/");
        FileInfo[] info = directory.GetFiles("*.pdf*");
        foreach(FileInfo f in info)
        {
            CreateFileButton(f.Name, f.CreationTime, Sprites.GetSprite(Sprites.TypeOfFile.pdf), SplitImage);
        }
    }
    public void CreateFileButton(string FileName, string FileInfo, Sprite TypeOfDoc, Image SplitImage)
    {
        Transform FileLinkTemplate = Instantiate(Template, Parent);
        RectTransform TemplateRectTransform = FileLinkTemplate.GetComponent<RectTransform>();
        FileLinkTemplate.Find("NameOfFile").GetComponent<TextMeshProUGUI>().SetText(FileName);
        FileLinkTemplate.Find("InfoText").GetComponent<TextMeshProUGUI>().SetText(FileInfo);
        FileLinkTemplate.Find("TypeOfDoc").GetComponent<Image>().sprite = TypeOfDoc;
        FileLinkTemplate.Find("SplitImage").GetComponent<Image>();
    }
}