Because Bluehost bundles hosting with domains, DNS edits there frequently happen alongside pointing a domain at Bluehost's servers or moving it away to another host. Ordinary record changes — updating an A record's IP, adding an MX or TXT record — carry a TTL that is commonly around an hour, so they are typically live within a few minutes to a few hours as caches expire across resolvers.
The longer wait comes when you change nameservers, either delegating your domain to Bluehost's nameservers or pointing it elsewhere. That delegation is cached at the TLD level and can take up to 24 to 48 hours to complete worldwide. If you are migrating a site to or from Bluehost, keep the old server reachable during that window so visitors who still resolve the old address are not met with an error.
Bluehost's control panel confirms edits immediately, but that only reflects its own authoritative servers. To know whether the change has actually reached the wider internet, query the record from multiple locations rather than trusting the dashboard's 'saved' message or your local browser cache, which can hold a stale answer well after propagation is complete.