Searching data older than a Date with typeORM

You can use MoreThan, the doc

async filesListToDelete(): Promise<any> {
  return await this.fileRepository.find({
   where: { 
       last_modified:  MoreThan('2018-11-15  10:41:30.746877') },
});}

Also you can do this using createQueryBuilder as below:

    public async filesListToDelete(): Promise<any> {
        let record = await this.fileRepository.createQueryBuilder('file')
            .where('file.last_modified > :start_at', { start_at: '2018-11-15  10:41:30.746877' })
            .getMany();

        return record
    }