With the support of the federal government, the uprising was suppressed by General Watter, approaching from the north. Based in Münster, his staff led the civil war in the Ruhr area. Units of the Reichswehr and Freikorps successfully suppressed the Red Ruhr Army. The fighting was followed by death sentences and mass executions. Those who were found carrying weapons at the time of their arrest were shot—including the wounded. On 3 April 1920, Reichspräsident Ebert forbade these summary executions. On 12 April 1920, General von Watter forbade his soldiers from engaging in "unlawful behaviour". The actions of both sides in the fighting have been described as showing "a maximum of cruelty". On 5 April, a large part of the Ruhr Army fled before the Reichswehr to the region occupied by the French Army. In response to the Reichswehr presence in the Ruhr, which contravened the Treaty of Versailles, the French occupied towns like Frankfurt, Hanau and Darmstadt on 6 April. The Reichswehr stopped itself only at the river Ruhr, as the British occupation forces were threatening to occupy the Bergisches Land due to the breach of the Versailles Treaty. By 8 April, the Reichswehr controlled all of the northern Ruhr area. By the end of the fighting, the participants in the uprising had lost in excess of 1,000 lives, the Reichswehr 208 dead and 123 missing, and Freikorps about 273 lives.
Question: On what 1/10 of a decade did somebody forbade the summary executions?
Answer: 1920