No date given, so the 1930's seem to be a good guess.
Text on Flickr:
Dairy Farm Ice & Cold Storage Kowloon
尖沙咀彌敦道74-78 號 74-78 Nathan Road
The first branch of Dairy Farm
1918年 九龍牛奶公司店舖啟用。
1941年 12月,日佔香港,店舖被日軍掠奪一空,業務停頓。
1945年 8月,香港重光,店舖業務逐漸恢復。
1958年 重建為文遜大廈(Manson House)。
1918 Dairy Farm Ice & Cold Storage Kowloon was opened.
1941-1945 Closed in Japanese Occupation
1958 rebuilt into Manson House, the name of founder of Dairy Farm Sir Patrick Manson (文遜醫生) and the name of the son of the new owner Henry Fok (霍英東), Manson Fok (霍文遜醫生)
Source:《圖說香港歷史建築1897-1919》