SQL Rebuild Indexes Handling
Try using Ola Halengren's SQL Server Maintenance Solution.

It has a lot of options, most important thing - it skips indexes that doesn't need maintenance (depending how You configure it).

There are few thing about index maintenance to remember. From my experience 3-4 days for full rebuilds on bigger databases isn't that much, depending on Your storage.

In some cases rebuild isn't needed, index reorganize is often enough for fragmentation between 5% and 30% (as stated in Microsoft recommendations in Books Online, and any kind of index maintenance is recommended only for indexes bigger than 1000 pages, while difference in performance might be noticable on indexes bigger than 50000 pages (as stated here).

In most cases index defragmentation isn't source of performance problems either, it just masks other issues hidden beneath. Defragmenting them too often won't improve Your performance and will stretch Your maintenance windows.

Another thing is, that maintenance creates noticeable load on IO and CPU, rebuild/reorganize operations are written in transaction log (for databases in FULL RECOVERY mode). So Your log files will get bigger, same with log backups.

More read about index maintenance on Brent Ozar's blog posts:

https://www.brentozar.com/archive/2012/08/sql-server-index-fragmentation/

https://www.brentozar.com/archive/2013/09/index-maintenance-sql-server-rebuild-reorganize/

https://www.brentozar.com/archive/2014/04/index-fragmentation-bad-statistics-arent-always-problem-video/