[Bug] Adaptive Card Chart.Line X-axis renders all values as 0 when using ISO 8601 timestamp on macOS Teams

Question

Summary

When sending an Adaptive Card with a Chart.Line element to Microsoft Teams, the X-axis fails to render correctly on the macOS Teams desktop app if the X-axis data contains ISO 8601 formatted timestamps (e.g., 2024-01-01T00:00:00). All X values are collapsed to 0, resulting in a vertical line being drawn at position 0 instead of a proper time-series line chart.

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Environment

• Platform: macOS (Teams Desktop App)
• Feature: Adaptive Card — Chart.Line
• Adaptive Cards Schema Version: 1.4

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Actual Behavior

All X-axis data points are interpreted as 0, causing all data points to be plotted on the Y-axis at X = 0. The chart appears as a single vertical line rather than a time-series chart.

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Sample Payload

"body": {
        "type": "message",
        "attachments": [
            {
                "contentType": "application/vnd.microsoft.card.adaptive",
                "content": {
                    "$schema": "http://adaptivecards.io/schemas/adaptive-card.json",
                    "type": "AdaptiveCard",
                    "version": "1.4",
                    "body": [
                        {
                            "type": "TextBlock",
                            "text": "윙크 데일리 알람",
                            "weight": "Bolder",
                            "size": "Large",
                            "color": "Good"
                        },
                        {
                            "type": "Container",
                            "items": [
                                {
                                    "type": "Chart.Line",
                                    "title": "Sample",
                                    "xAxisTitle": "Date",
                                    "yAxisTitle": "Sales",
                                    "colorSet": "categorical",
                                    "yMin": 20,
                                    "yMax": 130,
                                    "data": [
                                        {
                                            "legend": "Outlook",
                                            "values": [
                                                {
                                                    "x": "2026-04-01T00:10:00",
                                                    "y": 99
                                                },
                                                {
                                                    "x": "2026-04-01T00:20:00",
                                                    "y": 63
                                                },
                                                {
                                                    "x": "2026-04-01T00:30:00",
                                                    "y": 112
                                                },
                                                {
                                                    "x": "2026-04-01T00:40:00",
                                                    "y": 32
                                                },
                                                {
                                                    "x": "2026-04-01T00:50:00",
                                                    "y": 75
                                                },
                                                {
                                                    "x": "2026-04-01T01:00:00",
                                                    "y": 44
                                                }
                                            ]
                                        },
                                        {
                                            "legend": "Teams",
                                            "values": [
                                                {
                                                    "x": "2026-04-01T00:10:00",
                                                    "y": 48
                                                },
                                                {
                                                    "x": "2026-04-01T00:20:00",
                                                    "y": 82
                                                },
                                                {
                                                    "x": "2026-04-01T00:30:00",
                                                    "y": 39
                                                },
                                                {
                                                    "x": "2026-04-01T00:40:00",
                                                    "y": 101
                                                },
                                                {
                                                    "x": "2026-04-01T00:50:00",
                                                    "y": 43
                                                },
                                                {
                                                    "x": "2026-04-01T01:00:00",
                                                    "y": 80
                                                }
                                            ]
                                        },
                                        {
                                            "legend": "Copilot",
                                            "values": [
                                                {
                                                    "x": "2026-04-01T00:10:00",
                                                    "y": 96
                                                },
                                                {
                                                    "x": "2026-04-01T00:20:00",
                                                    "y": 123
                                                },
                                                {
                                                    "x": "2026-04-01T00:30:00",
                                                    "y": 27
                                                },
                                                {
                                                    "x": "2026-04-01T00:40:00",
                                                    "y": 54
                                                },
                                                {
                                                    "x": "2026-04-01T00:50:00",
                                                    "y": 45
                                                },
                                                {
                                                    "x": "2026-04-01T01:00:00",
                                                    "y": 62
                                                }
                                            ]
                                        }
                                    ]
                                }
                            ]
                        }
                    ]
                }
            }
        ]
    }

Answer 1

Hi @정성원

First, I’d like to clarify that this is a user‑to‑user support forum. Moderators participating here do not have access to backend systems, nor can we directly intervene in Microsoft product functionality. Our role is limited to providing technical guidance and sharing best‑practice recommendations based on reported issues, requests, and scenarios.     

Currently, I have not identified any official announcement or documentation from Microsoft that explicitly confirms this behavior related to ISO 8601 formatted timestamps in Adaptive Card Chart.Line yet. 

Based on my research, this issue might relate to the Adaptive Cards rendering engine on certain Microsoft Teams clients. Specifically, the renderer does not seem to correctly handle X‑axis values when the data type is not a pure numeric value. In cases where an ISO 8601 formatted timestamp is used (as your description, "2026-04-01T00:10:00"), the value may be implicitly coerced into a numeric type. Because the value contains non‑numeric characters, this coercion can fail and result in a value of 0, causing all X‑axis points to collapse at the same position. 

However, I have also confirmed through testing from my end that simple non‑numeric labels, such as DD/MM (for example, "01/04", "02/04"), work as expected. In this scenario, the renderer appears to treat the X values as categorical labels and assigns internal indexes (0, 1, 2, and so on), allowing the chart to render correctly. 

Please note that this summary is based on my own findings and may not fully address your concerns. To help you reach your goal more effectively, I recommend engaging with  [GitHub Community Forum] for a deeper technical dive or to connect with individuals who have relevant experience and expertise. Some approaches may behave differently or be restricted depending on your specific environment and configuration. These forums include many experienced developers and Microsoft specialists who can assist with troubleshooting and guidance.   

Apologies for redirecting you to the related development team support. As moderators in this community, we do not have access to your specific tenant configuration, and my testing environment is limited. Therefore, my guidance is based on available Microsoft documentation and resources. That said, I’ll do my best to provide additional insight where possible.   

I hope this helps.   

If you have any additional concerns, feel free to comment below. I would be more than happy to assist.  

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Answer 2

Charts in Adaptive Cards are documented as supporting several chart types, including Chart.Line, but the documentation does not define support for ISO 8601 timestamps or any specific non-numeric X-axis format for Chart.Line. The Chart.Line element is described only in terms of its general properties (such as color, colorSet, data, layout, visibility, and fallback), and there is no mention of date/time handling or platform-specific behavior.

Because of this, the behavior seen on macOS Teams—where ISO 8601 timestamp values for x are effectively treated as 0—is not something that can be corrected or worked around using documented schema options. It is a host implementation behavior rather than a schema-level feature that can be configured.

Given the current documentation, the only reliable approach is to treat the X-axis as numeric or categorical data that is known to be supported by the Teams host implementation, and to avoid relying on ISO 8601 timestamps as X values until the Teams client adds explicit support or the Adaptive Cards charting documentation is updated to describe date/time handling.

For tracking or escalation, this scenario should be reported as a Teams client bug or limitation for the Chart.Line host implementation on macOS, since the Adaptive Cards schema itself does not provide a way to change how the X-axis parses timestamp strings.

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References:

• Charts in Adaptive Cards
• Line chart