How can I pull the text that follows after a nested span? Specifically, I am trying to web scrape the text element that reads 2007-05-02
<td style="width: 33%"><span class="label">Start Date<span class="info-tip startdatetip">*</span>:</span> 2007-05-02</td>
My code gives me an AttributeError: 'NoneType' object has no attribute 'next_sibling'
    from bs4 import BeautifulSoup
    import urllib.request
    import csv
    source = urllib.request.urlopen('https://www.clinicaltrialsregister.eu/ctr-search/search? 
    query=&page=1').read()
    soup = BeautifulSoup(source, 'lxml')
    Start_date=soup.find('span',{'class':'label'}, text = 'Start Date').next_sibling
    print(Start_date)
Alternatively, I tried the code below which gives me none reference
Start_date=soup.find('span',{'class':'info-tip startdatetip'}).next_sibling.next_sibling
print(Start_date)
 
    