Last date label hidden on Time Series X-axis #39899

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1. dosubot

   added

   #bug:cosmeticCosmetic/layout/design tweak neededCosmetic/layout/design tweak needed

   viz:charts:timeseriesRelated to TimeseriesRelated to Timeseries

   on May 6, 2026
2. dosubot commented on May 6, 2026

   

   dosubotBot

   on May 6, 2026 – with DosuBot

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   This is a known and actively-discussed issue. You actually raised this same topic in Discussion #39361, where it was explored in detail [1].

   Root cause: ECharts' hideOverlap: true setting aggressively suppresses the last label when it detects potential overlap at the axis boundary. Despite several fixes merged in early 2026 (PR #37755, PR #38733, PR #38979), there's a discrepancy between those PRs and the current codebase — showMaxLabel does not appear to be set in the current transformProps.ts [2]. The showMaxLabel approach has a troubled history: it was added, reverted (PR #24995) due to "phantom labels," and subsequent fixes evolved away from it.

   Current state: There is no deterministic user-facing configuration that guarantees the last time label is always shown [1]. The available workarounds are:

   1. Apply non-zero X-axis label rotation (e.g., 45°) — triggers hideOverlap: false in newer builds
   2. Increase chart width to reduce overlap detection
   3. Theme-level override (Superset 6.0+) — use echartsOptionsOverridesByChartType to inject showMaxLabel: true globally if you control the deployment
   4. Cast date column to STRING at the dataset level and set "X Axis Label Interval → All" to bypass time-scale overlap logic entirely

   For your monitoring dashboard use case where the latest timestamp must always be visible, a feature request for an exposed showMaxLabel toggle or a dedicated "Always show last label" control would be well-motivated. The infrastructure partially exists — extending the ECharts Options JS editor (currently available for Evolution chart types) to Time-Series charts would also address this.

   To reply, just mention @dosu.

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3. Cloud-Architect-Emma commented on May 6, 2026

   

   Cloud-Architect-Emma

   on May 6, 2026

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   Hi @aijung0331 , thanks for raising the issue, i'd like to help fix this issue . Can you assign it to me ?

   👍React with 👍1Reacted by AJH
4. prathamesh04

   added a commit that references this issue on Jul 22, 2026

   fix: disable hideOverlap when showMaxLabel is active on time axes (ap…

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   e5a32e8
5. prathamesh04

   added a commit that references this issue on Jul 30, 2026

   test(mixed-timeseries): add x-axis label overlap test for apache#39899

   b6fda4b
6. rusackas

   added 3 commits that reference this issue on Aug 3, 2026

   fix: disable hideOverlap when showMaxLabel is active on time axes (ap…

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   3f463aa

   test(mixed-timeseries): add x-axis label overlap test for apache#39899

   d74f143

   fix: set timeGrainSqla in the apache#39899 MixedTimeseries regression…

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   eea4fd1
7. bikash-barnwal commented on Aug 14, 2026

   

   bikash-barnwal

   on Aug 14, 2026

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   Worth flagging before someone fixes this the obvious way: the obvious fix reopens #39972.

   The x-axis currently forces the trailing label only when a time grain is set (Timeseries/transformProps.ts, mirrored in MixedTimeseries):

   const showMaxLabel =
     xAxisType === AxisType.Time &&
     xAxisLabelRotation === 0 &&
     !!resolvedTimeGrain;

   That !!resolvedTimeGrain is deliberate. #37181 added showMaxLabel so the last data point's label renders; #39972 then restricted it to grained axes, because with Time Grain = None ECharts' axis end is not aligned to anything sensible, the forced label lands on a sub-minute timestamp, and SMART_DATE renders it through its millisecond/second buckets — producing a phantom .345ms label after the last legitimate one. There is a test pinning exactly that (x-axis does not force showMaxLabel when no time grain is set).

   So simply dropping the grain condition trades this bug for that one.

   Which case is in your screenshot? If a time grain is set, showMaxLabel is already true and the missing label is a different mechanism — worth checking the dedup wrapper (it suppresses a trailing label that formats identically to the previous tick) or plain label overflow/interval. If Time Grain is None, then the label is being suppressed on purpose by #39972 and the fix has to make the axis edge meaningful rather than force a label onto an arbitrary one — e.g. clamping the axis max to the last data point, or formatting the boundary label at the resolved data granularity instead of letting SMART_DATE fall into its sub-second buckets.

   Happy to implement the second approach if maintainers agree that's the right direction; I did not want to send a PR that silently reverts a merged fix.
8. sadpandajoe

   added a commit that references this issue on Aug 21, 2026

   fix: last date label hidden on time series x-axis (#39899) (#42299)

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   d422f5b
9. sadpandajoe

   closed this as completedin #42299on Aug 21, 2026
10. EnxDev

    added a commit that references this issue on Aug 28, 2026

    fix(echarts): align pinned axis labels with capped ticks, extract sha…

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    6dad5c9
11. sadpandajoe

    added a commit that references this issue on Sep 1, 2026

    fix(echarts): thin overlapping x-axis time labels on timeseries charts

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    bb4bdb2