EonNext app an hour out, using GMT not BST for calculating daily usage

  • WizzyWigg's Avatar
    Level 81
    @WizzyWigg

    With you there, mate. Can't beat a stub of pencil, the back of an envelope and a few grey cells.
    Thought you might be. 😂 It certainly keeps what remaining grey cells I have alive. 👴
  • geoffers's Avatar
    Level 29
    @retrotecchie

    Hmmmm - with the greatest of respect I'm afraid I have to disagree. I accept that all the DCC data is based on GMT the whole year round but people on multiple rates tariffs changing at midnight will be expecting to switch their devices on at midnight BST.

    So this explains why the EonNext app is showing the values which my spreadsheet calculations agree with when calculated using the GMT timings

    My charger started at midnight BST, however the DCC data shows the charger starting at 2300 GMT on the previous day. Therefore that has data is included in the previous day"s total shown on the app, and would potentially be charged at the higher daytime rate.

    Are you suggesting that to apply the next drive EV tariff, in the winter I will have to set my charger to start between midnight and 7 am, but in the summer I will have to set it to start between 1:00 a.m. and 8 am to get the correct overnight EV charging tariff.

    I'm happy that if this is the case so be it, but I'm sure it will cause a lot of grief to other new users who aren't aware of this.

    It's not really an issue for single a single rate tariffs, but clearly is an issue for tariffs starting with a cheap rate at midnight
    My assumption when I originally posted this was that the meter had the timings in BST and somehow the DCC was correcting to GMT.

    However I've now learned that although the meter does show the local time in BST, all the data it records and passes through to Eon etc via the DCC is in UTC/GMT

    This is from the SMETS2 specification...

    5.4.8.7 Daily read data
    ESME shall be capable of taking a copy of and storing the Tariff TOU Register Matrix(5.6.4.34), the Tariff TOU Block Register Matrix(5.6.4.35), the Active Import Register(5.6.4.3) and the Active Export Register(5.6.4.2) together with a UTC date and time stamp in the Daily Read Log(5.6.4.13) every day at midnight UTC.

    If operating in Prepayment Mode ESME shall be capable of recording the MeterbBalance(5.6.4.24), Emergency Credit Balance(5.6.4.15), Accumulated Debt Register(5.6.4.1), Payment Debt Register(5.6.4.25) and Time Debt Registers [1 …2](5.6.4.36) in the Prepayment Daily Read Log(5.6.4.27) every day at midnight UTC.

    5.4.8.8 Daily Consumption data
    ESME shall be capable of calculating and storing Consumption for the previous Day together with a UTC date stamp in the the Daily Consumption Log(5.6.4.14) every Day at midnight Local Time.

    5.4.8.9 Half hour profile data
    ESME shall be capable of recording in each 30 minute period (commencing at the start of minutes 00 and 30 in each hour), the following information (including the UTC date and time at the end of the 30 minute period to which the data relates) in the Profile Data Log(5.6.4.28):
    i. Consumption