diff --git a/rendercv/utilities.py b/rendercv/utilities.py
index 6327cc0..6652f49 100644
--- a/rendercv/utilities.py
+++ b/rendercv/utilities.py
@@ -5,7 +5,6 @@ import os
 
 from ruamel.yaml import YAML
 
-from . import data_models as dm
 from .terminal_reporter import warning, error, information
 
 
@@ -64,7 +63,7 @@ def escape_latex_characters(sentence: str) -> str:
     return sentence
 
 
-def parse_date_string(date_string: str) -> Date | int:
+def parse_date_string(date_string: str) -> Date:
     """Parse a date string in YYYY-MM-DD, YYYY-MM, or YYYY format and return a
     datetime.date object.
 
@@ -80,38 +79,17 @@ def parse_date_string(date_string: str) -> Date | int:
         # Then it is in YYYY-MM format
         # Assign a random day since days are not rendered in the CV
         date = Date.fromisoformat(f"{date_string}-01")
-    elif re.match(r"\d{4}", date_string):
-        # Then it is in YYYY format
-        # Then keep it as an integer
-        date = int(date_string)
     else:
         raise ValueError(
             f'The date string "{date_string}" is not in YYYY-MM-DD, YYYY-MM, or YYYY'
             " format."
         )
 
-    if isinstance(date, Date):
-        # Then it means the date is a Date object, so check if it is a past date:
-        if date > Date.today():
-            raise ValueError(
-                f'The date "{date_string}" is in the future. Please check the dates.'
-            )
-    elif isinstance(date, int):
-        # Then it means the date is an integer, so check if it is a past date:
-        if date > Date.today().year:
-            raise ValueError(
-                f'The date "{date_string}" is in the future. Please check the dates.'
-            )
-    elif not isinstance(date, str):
-        raise RuntimeError(
-            "This error shouldn't have been raised. Please open an issue on GitHub."
-        )
-
     return date
 
 
-def format_date(date: Date | int) -> str:
-    """Formats a date to a string in the following format: "Jan. 2021".
+def format_date(date: Date) -> str:
+    """Formats a `Date` object to a string in the following format: "Jan. 2021".
 
     It uses month abbreviations, taken from
     [Yale University Library](https://web.library.yale.edu/cataloging/months).
@@ -130,13 +108,6 @@ def format_date(date: Date | int) -> str:
     Returns:
         str: The formatted date.
     """
-    if not isinstance(date, (Date, int)):
-        raise TypeError("date is not a Date object or an integer!")
-
-    if isinstance(date, int):
-        # Then it means the user only provided the year, so just return the year
-        return str(date)
-
     # Month abbreviations,
     # taken from: https://web.library.yale.edu/cataloging/months
     abbreviations_of_months = [
@@ -155,47 +126,8 @@ def format_date(date: Date | int) -> str:
     ]
 
     month = int(date.strftime("%m"))
-    monthAbbreviation = abbreviations_of_months[month - 1]
-    year = date.strftime("%Y")
-    date_string = f"{monthAbbreviation} {year}"
+    month_abbreviation = abbreviations_of_months[month - 1]
+    year = date.strftime(format="%Y")
+    date_string = f"{month_abbreviation} {year}"
 
     return date_string
-
-
-def read_input_file(file_path: str) -> dm.RenderCVDataModel:
-    """Read the input file and return an instance of RenderCVDataModel.
-
-    Args:
-        file_path (str): The path to the input file.
-
-    Returns:
-        str: The input file as a string.
-    """
-    start_time = time.time()
-    information(f"Reading and validating the input file {file_path} has started.")
-
-    # check if the file exists:
-    if not os.path.exists(file_path):
-        raise FileNotFoundError(f"The input file {file_path} doesn't exist.")
-
-    # check the file extension:
-    accepted_extensions = [".yaml", ".yml", ".json", ".json5"]
-    if not any(file_path.endswith(extension) for extension in accepted_extensions):
-        raise ValueError(
-            f"The file {file_path} doesn't have an accepted extension!"
-            f" Accepted extensions are: {accepted_extensions}"
-        )
-
-    with open(file_path) as file:
-        yaml = YAML()
-        raw_json = yaml.load(file)
-
-    data = RenderCVDataModel(**raw_json)
-
-    end_time = time.time()
-    time_taken = end_time - start_time
-    information(
-        f"Reading and validating the input file {file_path} has finished in"
-        f" {time_taken:.2f} s."
-    )
-    return data