In which case, it would be in July 19, or maybe in July '19. Having said that, I would never write it that way if I meant the year, for fear of being misunderstood. But some could, especially in a text about the early 20th century, or the post WWI era. That's why background is important. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.