Anyone can say “we gotta get this done
Telling a developer to essentially "hurry up" won't get things done faster, it will just annoy the developer, or perhaps make them hurry and write sloppy code which will cost you more in the long run.
While I'm certainly no management expert, I'd expect at least a few questions you could ask any developer are:
- Everything considered (other tasks, meetings, misc distractions, research time, expected delays, possible overtime) - what date and time can the developer have this done by? Note that you want a date, not "how many hours do you think this will take". An 8-hour task may spread across 3 days if there are other distractions. Get an honest, unrushed date based on the developer's estimate. Note that you also want a time. Does "Wednesday" mean 8:00am, or midnight? This also gives the developer a concrete goal to shoot for, as opposed to "get it done real fast".
- Is there anything that can help the developer get this done faster (delegate sub-tasks, better hardware/software, tools, a technical roadblock holding you up, pair programming with another dev)? The goal is for the manager to offer practical help by shifting around resources. If this task is really so important, then it is important enough to provide extra resources too.
- Acknowledging that surprises do come up, so you understand if the date cannot be met, but the developer should at least alert you as soon as they reasonably think they can no longer meet the date - and provide an updated estimate. The goal is to not get suddenly surprised on the target date with a late feature.
Of course, it also helps to work in smaller increments with verifiable milestones along the way. It can be easier to manager 5 small 1-week "milestones" than a single big 1-month project.
All of these involve give and take. Yes you can have it be a certain date, but the developer determines what that date is. Yes you can have it earlier, but you need to provide the developer more resources. Yes you won't be surprised on the target date with bad news, but that's because the developer is encouraged to tell you the bad news up front.