'date:Y-m-d', 'end_date' => 'date:Y-m-d', 'due_date' => 'date:Y-m-d', 'created_at' => 'datetime', 'updated_at' => 'datetime', ]; public function student(): BelongsTo { return $this->belongsTo(Student::class); } public function unit(): BelongsTo { return $this->belongsTo(Unit::class); } public function classPackageUnit(): BelongsTo { return $this->belongsTo(ClassPackageUnit::class); } }