user78: Suppose I want to search for a transaction of exactly 445 BTC in the date range 27 July 2013 and Aug 3rd 2013 ... is there an (online?) tool that has this kind of search capabilities?

user95422: Blockchair allow you to query the bitcoin blockchain with lots of parameter such as date, BTC output amount, fee amount etc...
Here is your request:
https://blockchair.com/bitcoin/transactions?q=time(2013-07-27..2013-08-03),output_total(44500000000)#
Unfortunately it bring no result but you can change the parameters

78: <p>Suppose I want to search for a transaction of <a href="http://www.reddit.com/r/Bitcoin/comments/1j7y2y/yesterday_i_represented_a_client_who_paid_445/" rel="noreferrer">exactly 445 BTC</a> in the date range 27 July 2013 and Aug 3rd 2013 ... is there an (online?) tool that has this kind of search capabilities?</p>
 95422: <p><a href="https://blockchair.com/bitcoin" rel="nofollow noreferrer">Blockchair</a> allow you to query the bitcoin blockchain with lots of parameter such as date, BTC output amount, fee amount etc...</p>

<p>Here is your request:
<a href="https://blockchair.com/bitcoin/transactions?q=time(2013-07-27..2013-08-03),output_total(44500000000)#" rel="nofollow noreferrer">https://blockchair.com/bitcoin/transactions?q=time(2013-07-27..2013-08-03),output_total(44500000000)#</a></p>

<p>Unfortunately it bring no result but you can change the parameters</p>
