“经常在白天地”这种表述稍显口语化且不太完整规范，推测想表达的意思可能是“经常在白天（的时候）” ，英语可以表达为 “often during the day” 或者 “frequently in the daytime” 。
例句：
He often does exercise during the day.（他经常在白天锻炼。）
She frequently reads books in the daytime.（她经常在白天看书。 ）