LibreOffice bashes Microsoft for "absurd" OOXML format and Excel's handling of dates

LibreOffice developer, The Document Foundation (TDF), has historically had an ax to grind with Microsoft, which isn't at all surprising considering that the two offer competing products and champion different standards. LibreOffice leverages the open-source OpenDocument Format (ODF) for productivity documents, while Microsoft Office relies on the "open" OOXML format. TDF regularly calls out the Redmond tech giant for forcing customers to use Office formats, and now, it has bashed the company once again in a lengthy blog post.

TDF claims that ODF ensures digital sovereignty since it is an open-source format that cannot be controlled by a single vendor. Any document created in this format remains the sole property of the author since no vendor can independently change the format and inconvenience users. It emphasizes that this is very different from Microsoft's OOXML structure used in Office documents, which it says is only "open" on paper, but proprietary in practice.

LibreOffice's developer notes that OOXML was developed behind closed doors at Microsoft, and it is actually an insult to the community since it isn't transparent and discourages consultation, especially considering that its explainer document is over 7,500 pages long. TDF has highlighted that OOXML is not versioned and does not rely on independent standards. In fact, it alleges that Microsoft utilizes proprietary formats whenever possible.

The developer has also taken a dig at Microsoft's handling of dates with OOXML. It says that OOXML is so absurd in complexity that it cannot even handle the Gregorian calendar. Excel, in particular, gets dates wrong frequently, incorrectly identifies the year 1900 as a leap year, and when it "gets dates wrong, no other software does it worse."

TDF highlights that the only reason that so many people use Microsoft Office and OOXML today is that Microsoft employed a bait-and-switch strategy in a calculated and nefarious manner. It convinced the International Organization for Standardization (ISO), politicians, and, by extension, the world, that OOXML is a transitional format that will become strict, non-proprietary, and standard after 2010. That never happened, which brings us to where we are today, where Microsoft enjoys a monopoly on user-created documents. TDF claims that Microsoft lobbied with its partners like SAP to lock people into OOXML to the point that:

The HUGO Gene Nomenclature Committee was forced in 2020 to rename dozens of human genes – including SEPT1 and MARCH1 – because Excel kept silently converting their symbols to dates. Rather than going to Microsoft and demanding a bug fix, scientists preferred to throw years of established nomenclature down the drain to avoid upsetting Redmond. A revealing precedent.

The LibreOffice developer says that it's simply not enough for products to support ODF, they have to make it the native option, otherwise, digital sovereignity is "provisional at best". It has emphasized that it is actually OOXML that needs to be the interoperability format that should be used for document exchange with customers who continue to use the proprietary standard out of convenience or ignorance. The firm ends its detailed blog post by highlighting that any option other than the one described by it is false digital sovereignty.