Shopify releases their earnings on a quarterly basis. Generally, their earnings are released in the morning of the first day of the month following the end of each quarter. For the first two quarters of 2019, the release dates were April 30th and July 31st. For the 3rd quarter earnings, they will be released on October 31st.
It’s important to note that the actual timestamps of the releases vary. The press releases and other financial information are usually available right after the releasing date, at 4:05 PM Eastern Time. For example, the July 31st earnings were released around 7:30 PM Eastern Time.
You can check Shopify's Investor Relations page for an exact timeline of all upcoming earnings announcements.