Does fasting start right on the 12:00 am dot on Ash Wednesday, or is it after service at night?

Does fasting start right on the 12:00 am dot on Ash Wednesday, or is it after service at night? So confused. Thanks.

Starts at midnight on Ash Wednesday and continues for the next 24 hours ending at midnight on Thursday.

The liturgical day starts and ends at sunset, so when the sun is down on Tuesday Ash Wednesday has begun and when it goes down on Wednesday then it is over, but if you started at midnight it would probably be best to keep fast till the next midnight.

Usually I like to start a fast before midnight and end it at breakfast, so that it’s longer than 24 hours. Like, thirty hours or so. I think it’s against the spirit of self-sacrifice to eat until midnight and start up again 24 hours later.

Same thing with the short fast before Communion. Make it a little longer than one hour before and 15 minutes after receiving.

The fasting is for the calendar day of Wednesday. No more, no less.

However, to abide by the spirit of the discipline, that would also mean not staying up until 00:01am on Thursday and then splurging on a feast either.

If you have normal waking hours then it’s basically the waking day.

For shift workers, that presents different problems!

Liturgical days only count for Sundays and Solemnities. Otherwise, it’s midnight to midnight.

This is not correct. Ash Wednesday is not a solemnity and has no Evening Prayer I. Further, penitential disciplines are a matter of canon law, not liturgical law and for canon law, a day is runs midnight to midnight. The obligation to fast and abstain for Ash Wednesday begins at midnight and runs to 11:59:59 PM.

Would you be so kind then as to quote the canon which defines a day? I googled a few times but couldn’t find it.

Edit: nevermind I found it:
Title XI. Computation of Time

Can. 200 Unless the law expressly provides otherwise, time is to be computed according to the norm of the following canons.

Can. 201 §1. Continuous time is understood as that which undergoes no interruption.
§2. Useful time is understood as that which a person has to exercise or to pursue a right, so that it does not run for a person who is unaware or unable to act.

Can. 202 §1. In law, a day is understood as a period consisting of 24 continuous hours and begins at midnight unless other provision is expressly made; a week is a period of 7 days; a month is a period of 30 days, and a year is a period of 365 days unless a month and a year are said to be taken as they are in the calendar.
§2. If time is continuous, a month and a year must always be taken as they are in the calendar.

Can. 203 §1. The initial day (a quo) is not computed in the total unless its beginning coincides with the beginning of the day or the law expressly provides otherwise.
§2. Unless the contrary is established, the final day (ad quem) is computed in the total which, if the time consists of one or more months or years, or one or more weeks, is reached at the end of the last day of the same number or, if a month lacks a day of the same number, at the end of the last day of the month.

It would seem I was incorrect regarding the liturgical day as well which also runs from midnight to midnight.
From the General Norms for the Liturgical Year and the Calendar:
I. The Liturgical Day in General

  1. Each day is made holy through the liturgical celebrations of the people of God, especially through the eucharistic sacrifice and the divine office.

The liturgical day runs from midnight to midnight, but the observance of Sunday and solemnities begins with the evening of the preceding day.

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