PHEP 3 Support Schedule
This page provides a visual timeline and schedule for PHEP 3, PyHC’s Python and Upstream Package Support Policy (based on SPEC 0).
Support Policy Summary
All PyHC packages should:
- Support Python versions for at least 36 months (3 years) after their initial release
- Support upstream core Scientific Python packages for at least 24 months (2 years) after their initial release
- Adopt support for new versions within 6 months of their release
The upstream core Scientific Python packages are:
numpy, scipy, matplotlib, pandas, scikit-image, networkx, scikit-learn, xarray, ipython, zarr
Support Window Timeline
gantt
dateFormat YYYY-MM-DD
axisFormat %m / %Y
title Support Window
section python
3.11 : 2022-10-24,2025-10-23
3.12 : 2023-10-02,2026-10-01
3.13 : 2024-10-07,2027-10-07
3.14 : 2025-10-07,2028-10-06
section numpy
1.25.0 : 2023-06-17,2025-06-16
1.26.0 : 2023-09-16,2025-09-15
2.0.0 : 2024-06-16,2026-06-16
2.1.0 : 2024-08-18,2026-08-18
2.2.0 : 2024-12-08,2026-12-08
2.3.0 : 2025-06-07,2027-06-07
2.4.0 : 2025-12-20,2027-12-20
section scipy
1.11.0 : 2023-06-25,2025-06-24
1.12.0 : 2024-01-20,2026-01-19
1.13.0 : 2024-04-02,2026-04-02
1.14.0 : 2024-06-24,2026-06-24
1.15.0 : 2025-01-03,2027-01-03
1.16.0 : 2025-06-22,2027-06-22
1.17.0 : 2026-01-10,2028-01-10
section matplotlib
3.8.0 : 2023-09-15,2025-09-14
3.9.0 : 2024-05-15,2026-05-15
3.10.0 : 2024-12-14,2026-12-14
section pandas
2.0.0 : 2023-04-03,2025-04-02
2.1.0 : 2023-08-30,2025-08-29
2.2.0 : 2024-01-20,2026-01-19
2.3.0 : 2025-06-05,2027-06-05
3.0.0 : 2026-01-21,2028-01-21
section scikit-image
0.21.0 : 2023-06-02,2025-06-01
0.22.0 : 2023-10-03,2025-10-02
0.23.0 : 2024-04-10,2026-04-10
0.24.0 : 2024-06-18,2026-06-18
0.25.0 : 2024-12-13,2026-12-13
0.26.0 : 2025-12-20,2027-12-20
section networkx
3.1 : 2023-04-04,2025-04-03
3.2 : 2023-10-19,2025-10-18
3.3 : 2024-04-06,2026-04-06
3.4 : 2024-10-10,2026-10-10
3.5 : 2025-05-29,2027-05-29
3.6 : 2025-11-24,2027-11-24
section scikit-learn
1.3.0 : 2023-06-30,2025-06-29
1.4.0 : 2024-01-18,2026-01-17
1.5.0 : 2024-05-21,2026-05-21
1.6.0 : 2024-12-09,2026-12-09
1.7.0 : 2025-06-05,2027-06-05
1.8.0 : 2025-12-10,2027-12-10
section xarray
2023.4.0 : 2023-04-14,2025-04-13
2023.5.0 : 2023-05-19,2025-05-18
2023.6.0 : 2023-06-23,2025-06-22
2023.7.0 : 2023-07-17,2025-07-16
2023.8.0 : 2023-08-20,2025-08-19
2023.9.0 : 2023-09-26,2025-09-25
2023.10.0 : 2023-10-19,2025-10-18
2023.11.0 : 2023-11-17,2025-11-16
2023.12.0 : 2023-12-08,2025-12-07
2024.1.0 : 2024-01-17,2026-01-16
2024.2.0 : 2024-02-19,2026-02-18
2024.3.0 : 2024-03-29,2026-03-29
2024.5.0 : 2024-05-13,2026-05-13
2024.6.0 : 2024-06-13,2026-06-13
2024.7.0 : 2024-07-30,2026-07-30
2024.9.0 : 2024-09-11,2026-09-11
2024.10.0 : 2024-10-24,2026-10-24
2024.11.0 : 2024-11-22,2026-11-22
2025.1.0 : 2025-01-03,2027-01-03
2025.3.0 : 2025-03-20,2027-03-20
2025.4.0 : 2025-04-29,2027-04-29
2025.6.0 : 2025-06-10,2027-06-10
2025.7.0 : 2025-07-03,2027-07-03
2025.8.0 : 2025-08-14,2027-08-14
2025.9.0 : 2025-09-04,2027-09-04
2025.10.0 : 2025-10-06,2027-10-06
2025.11.0 : 2025-11-17,2027-11-17
2025.12.0 : 2025-12-05,2027-12-05
2026.1.0 : 2026-01-28,2028-01-28
2026.2.0 : 2026-02-13,2028-02-13
section ipython
8.13.0 : 2023-04-28,2025-04-27
8.14.0 : 2023-06-02,2025-06-01
8.15.0 : 2023-09-01,2025-08-31
8.16.0 : 2023-09-29,2025-09-28
8.17.0 : 2023-10-30,2025-10-29
8.18.0 : 2023-11-24,2025-11-23
8.19.0 : 2023-12-22,2025-12-21
8.20.0 : 2024-01-08,2026-01-07
8.21.0 : 2024-01-31,2026-01-30
8.22.0 : 2024-02-22,2026-02-21
8.23.0 : 2024-03-31,2026-03-31
8.24.0 : 2024-04-26,2026-04-26
8.25.0 : 2024-05-31,2026-05-31
8.26.0 : 2024-06-28,2026-06-28
8.27.0 : 2024-08-30,2026-08-30
8.28.0 : 2024-10-02,2026-10-02
8.29.0 : 2024-10-25,2026-10-25
8.30.0 : 2024-11-29,2026-11-29
8.31.0 : 2024-12-20,2026-12-20
8.32.0 : 2025-01-31,2027-01-31
8.33.0 : 2025-02-28,2027-02-28
8.34.0 : 2025-03-08,2027-03-08
8.35.0 : 2025-04-07,2027-04-07
8.36.0 : 2025-04-25,2027-04-25
8.37.0 : 2025-05-31,2027-05-31
8.38.0 : 2026-01-05,2028-01-05
9.0.0 : 2025-02-28,2027-02-28
9.1.0 : 2025-04-07,2027-04-07
9.2.0 : 2025-04-25,2027-04-25
9.3.0 : 2025-05-31,2027-05-31
9.4.0 : 2025-07-01,2027-07-01
9.5.0 : 2025-08-29,2027-08-29
9.6.0 : 2025-09-29,2027-09-29
9.7.0 : 2025-11-05,2027-11-05
9.8.0 : 2025-12-03,2027-12-03
9.9.0 : 2026-01-05,2028-01-05
9.10.0 : 2026-02-02,2028-02-02
section zarr
2.15.0 : 2023-06-14,2025-06-13
2.16.0 : 2023-07-20,2025-07-19
2.17.0 : 2024-02-14,2026-02-13
2.18.0 : 2024-05-07,2026-05-07
3.0.0 : 2025-01-09,2027-01-09
3.1.0 : 2025-07-15,2027-07-15
Drop and Adoption Schedule
Below is an auto-generated schedule with recommended dates for dropping support and adopting new versions. We suggest that the next release in a given quarter is considered as the one removing support for a given item.
You may want to delay the removal of support of an older Python version until your package fully works on the newly released Python, thus keeping the number of supported minor versions of Python the same for your package.
2025 - Quarter 3:
Adopt support for:
| |
|
|
| ipython |
8.32.0 to 9.0.0 |
support by Aug 2025 and Sep 2025 |
| scipy |
1.15.0 |
support by Jul 2025 |
| xarray |
2025.1.0 to 2025.3.0 |
support by Jul 2025 and Sep 2025 |
| zarr |
3.0.0 |
support by Jul 2025 |
Can drop support for:
| |
|
|
| ipython |
8.15.0 to 8.16.0 |
released Sep 2023 and Sep 2023 |
| matplotlib |
3.8.0 |
released Sep 2023 |
| numpy |
1.26.0 |
released Sep 2023 |
| pandas |
2.1.0 |
released Aug 2023 |
| xarray |
2023.7.0 to 2023.9.0 |
released Jul 2023 and Sep 2023 |
| zarr |
2.16.0 |
released Jul 2023 |
2025 - Quarter 4:
Adopt support for:
| |
|
|
| ipython |
8.35.0 to 9.4.0 |
support by Oct 2025 and Dec 2025 |
| networkx |
3.5 |
support by Nov 2025 |
| numpy |
2.3.0 |
support by Dec 2025 |
| pandas |
2.3.0 |
support by Dec 2025 |
| scikit-learn |
1.7.0 |
support by Dec 2025 |
| scipy |
1.16.0 |
support by Dec 2025 |
| xarray |
2025.4.0 to 2025.6.0 |
support by Oct 2025 and Dec 2025 |
Can drop support for:
| |
|
|
| ipython |
8.17.0 to 8.19.0 |
released Oct 2023 and Dec 2023 |
| networkx |
3.2 |
released Oct 2023 |
| python |
3.11 |
released Oct 2022 |
| scikit-image |
0.22.0 |
released Oct 2023 |
| xarray |
2023.10.0 to 2023.12.0 |
released Oct 2023 and Dec 2023 |
2026 - Quarter 1:
Adopt support for:
| |
|
|
| ipython |
9.5.0 to 9.6.0 |
support by Feb 2026 and Mar 2026 |
| xarray |
2025.7.0 to 2025.9.0 |
support by Jan 2026 and Mar 2026 |
| zarr |
3.1.0 |
support by Jan 2026 |
Can drop support for:
| |
|
|
| ipython |
8.20.0 to 8.23.0 |
released Jan 2024 and Mar 2024 |
| pandas |
2.2.0 |
released Jan 2024 |
| scikit-learn |
1.4.0 |
released Jan 2024 |
| scipy |
1.12.0 |
released Jan 2024 |
| xarray |
2024.1.0 to 2024.3.0 |
released Jan 2024 and Mar 2024 |
| zarr |
2.17.0 |
released Feb 2024 |
2026 - Quarter 2:
Adopt support for:
| |
|
|
| ipython |
9.7.0 to 9.8.0 |
support by May 2026 and Jun 2026 |
| networkx |
3.6 |
support by May 2026 |
| numpy |
2.4.0 |
support by Jun 2026 |
| python |
3.14 |
support by Apr 2026 |
| scikit-image |
0.26.0 |
support by Jun 2026 |
| scikit-learn |
1.8.0 |
support by Jun 2026 |
| xarray |
2025.10.0 to 2025.12.0 |
support by Apr 2026 and Jun 2026 |
Can drop support for:
| |
|
|
| ipython |
8.24.0 to 8.26.0 |
released Apr 2024 and Jun 2024 |
| matplotlib |
3.9.0 |
released May 2024 |
| networkx |
3.3 |
released Apr 2024 |
| numpy |
2.0.0 |
released Jun 2024 |
| scikit-image |
0.23.0 to 0.24.0 |
released Apr 2024 and Jun 2024 |
| scikit-learn |
1.5.0 |
released May 2024 |
| scipy |
1.13.0 to 1.14.0 |
released Apr 2024 and Jun 2024 |
| xarray |
2024.5.0 to 2024.6.0 |
released May 2024 and Jun 2024 |
| zarr |
2.18.0 |
released May 2024 |
2026 - Quarter 3:
Adopt support for:
| |
|
|
| ipython |
8.38.0 to 9.10.0 |
support by Jul 2026 and Aug 2026 |
| pandas |
3.0.0 |
support by Jul 2026 |
| scipy |
1.17.0 |
support by Jul 2026 |
| xarray |
2026.1.0 to 2026.2.0 |
support by Jul 2026 and Aug 2026 |
Can drop support for:
| |
|
|
| ipython |
8.27.0 |
released Aug 2024 |
| numpy |
2.1.0 |
released Aug 2024 |
| xarray |
2024.7.0 to 2024.9.0 |
released Jul 2024 and Sep 2024 |
2026 - Quarter 4:
Can drop support for:
| |
|
|
| ipython |
8.28.0 to 8.31.0 |
released Oct 2024 and Dec 2024 |
| matplotlib |
3.10.0 |
released Dec 2024 |
| networkx |
3.4 |
released Oct 2024 |
| numpy |
2.2.0 |
released Dec 2024 |
| python |
3.12 |
released Oct 2023 |
| scikit-image |
0.25.0 |
released Dec 2024 |
| scikit-learn |
1.6.0 |
released Dec 2024 |
| xarray |
2024.10.0 to 2024.11.0 |
released Oct 2024 and Nov 2024 |
2027 - Quarter 1:
Can drop support for:
| |
|
|
| ipython |
8.32.0 to 9.0.0 |
released Jan 2025 and Mar 2025 |
| scipy |
1.15.0 |
released Jan 2025 |
| xarray |
2025.1.0 to 2025.3.0 |
released Jan 2025 and Mar 2025 |
| zarr |
3.0.0 |
released Jan 2025 |
2027 - Quarter 2:
Can drop support for:
| |
|
|
| ipython |
8.35.0 to 9.3.0 |
released Apr 2025 and May 2025 |
| networkx |
3.5 |
released May 2025 |
| numpy |
2.3.0 |
released Jun 2025 |
| pandas |
2.3.0 |
released Jun 2025 |
| scikit-learn |
1.7.0 |
released Jun 2025 |
| scipy |
1.16.0 |
released Jun 2025 |
| xarray |
2025.4.0 to 2025.6.0 |
released Apr 2025 and Jun 2025 |
2027 - Quarter 3:
Can drop support for:
| |
|
|
| ipython |
9.4.0 to 9.6.0 |
released Jul 2025 and Sep 2025 |
| xarray |
2025.7.0 to 2025.9.0 |
released Jul 2025 and Sep 2025 |
| zarr |
3.1.0 |
released Jul 2025 |
2027 - Quarter 4:
Can drop support for:
| |
|
|
| ipython |
9.7.0 to 9.8.0 |
released Nov 2025 and Dec 2025 |
| networkx |
3.6 |
released Nov 2025 |
| numpy |
2.4.0 |
released Dec 2025 |
| python |
3.13 |
released Oct 2024 |
| scikit-image |
0.26.0 |
released Dec 2025 |
| scikit-learn |
1.8.0 |
released Dec 2025 |
| xarray |
2025.10.0 to 2025.12.0 |
released Oct 2025 and Dec 2025 |
2028 - Quarter 1:
Can drop support for:
| |
|
|
| ipython |
8.38.0 to 9.10.0 |
released Jan 2026 and Feb 2026 |
| pandas |
3.0.0 |
released Jan 2026 |
| scipy |
1.17.0 |
released Jan 2026 |
| xarray |
2026.1.0 to 2026.2.0 |
released Jan 2026 and Feb 2026 |
2028 - Quarter 4:
Can drop support for:
| |
|
|
| python |
3.14 |
released Oct 2025 |
For Package Maintainers
PyHC packages should:
- Clearly document their dependency version policy (see examples: PlasmaPy, SpacePy)
- Test against the minimum and maximum supported versions
- Avoid maximum or exact requirements (e.g.,
numpy<2 or matplotlib==3.5.3) unless absolutely necessary
- Not require versions of any dependency older than 24 months
This page is maintained by the PyHC Tech Lead. The schedule is generated using code from PHEP 3 and is updated periodically.