The ILO has adopted 25 Conventions and 14 non-binding Recommendations in the area of working time, beginning with its very first Convention on hours of work in 1919. These standards cover a wide range of subject matter including hours of work, weekly rest, paid annual leave, night work, and part-time work. Many of these standards are quite old; have been widely denounced (e.g., the Night Work (Women) Convention, 1919 (No. 4)); and/or have been replaced by newer standards. The most significant working time-related standards which remain in force are as follows: