Database design question: Tags with values(duration) linked to them

I am creating a database that takes in daily inputs such as: - Date - Events in that date (e.g. project foo: 5 hours, bar: 2 hours, etc...) - Rating of the date There's more but these are probably the only relevant inputs regarding the problem. The problem is how do I construct my tables so that I have stored somehow the specific duration an event lasts. Currently what I have is: - A users table storing user log in credentials (1) - A rating table to store input date, rating of the date, etc... (2) - A tags table storing unique tags (3) I will use the tags and ratings to look for possible patterns in the future in case that's relevant. I don't find it difficult at all if I just had to deal with tags alone related to specific dates, as I would just have to have an unique table of tags and associate the tag_id with a date. But I have no clue how I store the duration of a tag on a specific day efficiently. I could of course only use a single table, accept redundancy with overlapping tags on different days and store tags, events and duration in a single string field. But that doesn't seem efficient to me. I am very novice when it comes to databases and I appreciate the help. I am using Python 3.7.2, SQLite and Flask-SQLAlchemy 2.4.0 to construct the tables. Like so: (1) class User(db.Model): __tablename__ = 'user' id = db.Column(db.Integer, primary_key=True) username = db.Column(db.String(80), unique=True, nullable=False) email = db.Column(db.String(120), unique=True, nullable=False) password_hash = db.Column(db.String(128)) (2) class Rating(db.Model): __tablename__ = 'rating' id = db.Column(db.Integer, primary_key=True) date = db.Column(db.Date, unique=False, nullable=False) rating_day = db.Column(db.Integer, nullable=False) user_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=False) # etc... (3) class Tags(db.Model): __tablename__ = 'tags' id = db.Column(db.Integer, primary_key=True) tag = db.Column(db.Integer, unique=True, nullable=False)