What does YDAY mean?
If you want to know the YDAY meaning you should consider that this abbreviation can have several meanings depending on the context in which it is used, in this case this abbreviation can refer to:
Analyzing the different meanings that YDAY can have, we can see that generally the 4 characters that make up the abbreviation are equal to the first letters of the words that make up the meanings indicated in the list.
Does YDAY always means the same?
No. The meaning of YDAY does not have to be exclusively one of those listed above, as this abbreviation may have different meanings that have not been included. In other words, the abbreviation YDAY may be used for other connotations not included in the list, since depending on the language or country where this abbreviation is used it may have another or other meanings.
Therefore, if you ask yourself "What does YDAY mean?" you are probably referring to any of the names indicated, although it may be a different meaning according on the context or the language in which the abbreviation is used.
What are the abbreviations used for?
Abbreviations are used to shorten the name of something that is composed of several words in order to save letters when it is written. In this case the shorthand YDAY serves to shorten any of the definitions mentioned above without losing the meaning. In other words, you can use this name in an abbreviated form and be understood simply without having to mention the full name.