Respect Time Box and Cadence; Create Necessary Slack

The daily standup is part of the cadence of the Sprint. As such, it should be:

1. Held at a predictable time.
2. Strictly time-boxed.
3. Meeting the needs of the Development Team.
4. Facilitating collaboration rather than status reporting.

If people are routinely showing up late, at least one of the principles above is likely being violated. To address this, the Scrum Team should:

1. Review the start time of the standup to ensure it's consistent and agreeable to the whole team. About an hour after the starting time of core hours is often a good place to start.
2. Ensure the standup starts on time and ends on time, every time! Individuals being late shouldn't be allowed to disrupt the time box. Enforcing the time box is a key responsibility for an effective Scrum Master in their capacity as a process referee.
3. Address root causes and impediments. If people are late because meetings are too closely packed on the day's calendar, or insufficient padding around the event is provided by the organization, fix that!
4. Ensure the daily standup is used only for collaborating on the daily increment. Push status reporting and other topics outside of the meeting's time box. If the team members find value in the event, they'll make time for it and want to be there for the whole thing.

TL;DR

You don't describe your role on the Scrum Team, but the solutions require the active collaboration of all members of the team. In particular, the Scrum Master role is the process referee, and not simply a bystander separate from the rest of the Scrum Team. This is often obscured by a misunderstanding of the "servant leader" paradigm. As a coach and referee, the Scrum Master most likely needs to both explain and enforce the framework's requirements for the daily standup, rather than just taking a passive approach.

Respect Time Box and Cadence; Create Necessary Slack

The daily standup is part of the cadence of the Sprint. As such, it should be:

1. Held at a predictable time.
2. Strictly time-boxed.
3. Meeting the needs of the Development Team.
4. Facilitating collaboration rather than status reporting.

If people are routinely showing up late, at least one of the principles above is likely being violated. To address this, the Scrum Team should:

1. Review the start time of the standup to ensure it's consistent and agreeable to the whole team. About an hour after the starting time of core hours is often a good place to start.
2. Ensure the standup starts on time and ends on time, every time! Individuals being late shouldn't be allowed to disrupt the time box. Enforcing the time box is a key responsibility for an effective Scrum Master in their capacity as a process referee.
3. Address root causes and impediments. If people are late because meetings are too closely packed on the day's calendar, or insufficient padding around the event is provided by the organization, fix that!
4. Ensure the daily standup is used only for collaborating on the daily increment. Push status reporting and other topics outside of the meeting's time box. If the team members find value in the event, they'll make time for it and want to be there for the whole thing.