How long does clearing confirmation take

Got a place through clearing yesterday morning and am so pleased. Email confirmation came through at lunchtime and I logged into UCAS and put in info, logged into student finance and changed info. But so far nothing. Another uni also offered me a place but window of opportunity closes at 4. And can't apply for accommodation until application is processed. Plus there are open days tomorrow both for SH and for other uni. Obviously anxious here ... how much longer will I need to wait?