"If being GC is all about protecting women’s rights, please tell me how a transgender day of rememberance erodes your rights? "
It's very simple. Transwomen claim that they are/would be attacked in men's toilets, are at outlandish risk of murder/rape/etc., and therefore need extra legal rights (which come at the expense of natal females).
By presenting a narrative that tw are being killed, using TDoR, this attracts public sympathy, political support, etc. for their political goals.
On a very simple level, it works like this: white man says 'I'm a victim, give me more rights' - everybody laughs 'you're in the group that's exact opposite of victim'. But if said white man becomes a TW, they are able to successfully argue that they are in an out group and in need of special rights. And this comes despite the TW being in many cases very plainly enormously privileged.
As an example, John Ozimek as a man was simply a hardcore pornography advocate. That was fine, but nobody treated him as anything more than a rentaquote when they needed someone on some new pornography law or whatever. It was understood that John was a consumer/advocate for hardcore pornography, but nobody seriously imagined that John was oppressed.
However when John started identifying as Jane, suddenly the narrative changed, and Jane was able to identify as a feminist, a member of a victim group, and so on.
We have to look at where this insta-victim status comes from, because on a basic level, as a middle-class white journalist,
John/Jane is very plainly NOT a victim, nor someone at great risk of violence.
We know from police figures that transphobic violence is by far the rarest form of hate crime, and while, say Sajid Javid, as an Asian male, is at risk of random racial hate crime, I don't think we would recognise Sajid in our analysis as a 'victim', even though racial hate crime is at least 100x more common than transgender hate crime.
And I don't think we have a 'racist murder day of remembrance', even though there is a real risk of racial violence & murder in this country, and racially motivated murders are something that happen from time to time.
And again we have an epidemic of sexual violence and murder against women and girls and there is no day of remembrance there either.
So you have to look beyond 'these people just want to remember their dead friends', and actually look at the facts, look at who is celebrating these events, and what message is being sent out. If Thurrock Council are raising the transgender flag for TDoR, but the local police tell a woman not to walk home a certain route because she has experienced sexual violence from men on that route, and it's likely to be repeated, I'm not really sure what the message is being sent out there, but it's certainly not 'let's think about the safety of women and girls'.
Because let's be honest, the risk and fear of random sexual violence (quite outside domestic violence) is something that every woman and girl lives with for decades, and nobody's doing a damn thing about it other than saying 'get a taxi home' or whatever.
Now ok, on one level, if a transwoman is perceived as female by an attacker then that TW might be subject to a heightened risk of random sexual violence, as opposed to someone who just looks like a man, who in general don't worry about being raped AT ALL, but to somehow frame this as transphobic violence is quite the take, when the risk is literally only a function of the fact that the subject is perceived as a member of the female sex class, that is to say the subject of the overwhelming majority of sexual violence and murder. And not a day of remembrance in sight there.
The official recognition and observance of TDoR is the political favouring of one group (transwomen) with the intent to prioritise it over others (women).