Section, act June 29, 1950, ch. 404, 64 Stat. 275, provided for extension of time of annual assessment work, on mining claims in the United States, including Alaska, for period commencing July 1, 1949, until 12 o'clock noon Oct. 1, 1950, and also provided for commencement of assessment work or improvements required for year ending 12 o'clock noon July 1, 1951, immediately following 12 o'clock noon July 1, 1950. See sections 28b to 28e of this title.