xiāoxi lǐ xiě 'shíjiān gǎi dào qī diǎn, dìdiǎn bú biàn', bǐ zhǐ shuō 'gǎi le' qīngchu

消息里写“时间改到七点，地点不变”，比只说“改了”清楚。

Writing 'the time is changed to seven, and the location remains the same' in the message is clearer than just saying 'changed'