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In this task you will be given an answer to a question. You need to generate a question. The answer given should be a correct answer for the generated question.

Republican President Donald Trump and First Lady Melania Trump attended church services in observation of a special National Day of Prayer, which Trump previously declared, in support of the victims of Hurricane Harvey dwelling in the state of Texas, to 'uplift one another and assist those suffering from the consequences of this terrible storm.'
Output:
when was the last time a president declared a national day of prayer