People's Dates  eg., Albert Einstein (1884 -1955).
Note:  When you mention a person in a research paper or other scholarly text or article, their years of birth and death should immediately follow the name in parentheses.  That is to let the reader know exactly to whom you are referring, since there may be several individuals with the same name.
This standard practice can be helpful in another way, for since the Dictionary of Biography (the standard reference work on people) does not have entries for individuals who are still living, when you find the 'second date' after a name, you can be reasonably certain to find more about them in that book.

• We can use fl. which stands for the Latin floruit meaning 'flourished around' if we do not have their exact dates, eg.  Elvis Presley (fl. 1960.)
• There is no need to used b. [born] and d. [died] eg. R. Bing (b. 1938 - d. 2122) when there are two years mentioned; we know which is which.  However, if you know only one, you have to indicate if it is the b. or the d. date.
• A small c. with any date means it is not an exact one.  It stands for the Latin circa meaning around.

BCE & CE
BCE - stands for Before the Common Era, and has come to replace the older usage BC, meaning Before Christ.

You will still find both usages in texts, discussions, and online lectures depending upon the writer's personal preference (or agenda or hidden intent. [Some writers 'just don't get it' or are too old and rigid to change.  Some underestimate the intelligence of the general public.]

We will use the more inclusive BCE in our writing.
In your private communications, you may follow your own preference aware of the fact that to use the older form (only current since the late 1400's) connotes a definite Christian orientation.

• BC-AD  is not an appropriate form for use in an academic context in the 3rd millennium; it is not all-inclusive, and may even be contradictory or absurd in certain contexts:
• Yeshua bar Yosef's aka Jesus' approximate date of birth can be expressed as 4 BCE or 4 BC.
• You should know that in those few instances when it is appropriate to use AD (Anno Domini - year of the Lord)  it properly preceeds the number, ie. AD 2001 is this year.
• In documents within a Muslim context, AH (anno Hegirae) is used in that way, too.

• When we want others to notice an event in relation to today, we use BP (Before the Present).  It is used in the same sense as ago.  The battle of the Teutonborg Forest depicted in Gladiator took place 1,810 years BP (that is, in 190 CE.)

What does the C in CE stand for; who started this practice and when?

Edited from reply inHumanist Archives (1991) by D. Baron at Illinois U.:

[The Oxford English Dictionary - highest authority on usage in the English language
cites] ... an 1881 instance of BCE and an 1886 instance of CE,
as well as an 1825 use of C.AE. for `Christian Era.'
Dr. J.H. Marshall, Senior Assistant Editor of the New Shorter OED,
adds, "It is notable that all the sources are works of Jewish
history, and I suspect that CE for Christian Era [sic] was an initial
move away from the more overtly `partisan' AD. In fact, we have
very few examples of `common era' or of the abbreviations CE and
BCE, all from recent books on the history of non-Christian
religions or cultures (including Judaism and Sikhism). They
seem still to be used only in contexts where AD and BC would be
particularly incongruous, or by authors particularly reluctant
to use the Christian term."

Kathleen M. Doherty of Merriam-Webster Inc. writes there is very
little definitive information about these abbreviations. Both
Christian Era and Common Era are available expansions of C.E. and
have been since at least the 1909 _Webster's New International
Dictionary_. "C.E. common era seems to have become more widespread
especially in books dealing with theology over the last ten to
fifteen years."       [People also think of CE as a reference to the Contemporary Era.]

It's disappointing not to find a smoking lexicographical gun [like] a
text (early 19c seems likely) where the author says "I'm going
to coin CE/BCE because . . . "  [ie. There is no answer.]

• a) I'm not a Christian, or
• b) I don't believe in using Latin when native words will do, or
• c) A.D. just presents too many usage problems--does it go before or after, how do you use it with a century or a range of dates?
• d) I know how hard it is to deal with abbreviations in dictionaries..... [ :-p.]

Very Brief History of Current Calendar
Western time - that is, time as seen by heirs to the Roman world-view - is thought of as a linear unfolding, or a river.  Therefore, there must be established a starting point.  Other cultures see time as cyclical with no beginning or end, so calendars are merely convenient tools for establishing biographies and for communication purposes.  Ultimately, as long as it can reliably predict planting time, any calendar will do. Many cultures today use two calendars, a traditional usually religious one that is solar-lunar, and the Western one.

Dionysius Exiguus [Short Dennis] ( fl. 556 CE) a Scythian monk living in Rome , in trying to establish the most important anniversary for Christians, the day of Easter, began his calculation at 753 AUC (ab urbe condita -  since the founding of Rome) the year of the birth of Jesus as he believed it, according to accounts in the New Testament.  As zero as a place-marker in writing numbers was not yet in use in Europe, and for other reasons, this 'Julian' calendar had to be adjusted.

There is no specific moment in history when the use of BC and AD took hold.  In fact, that was not prevalent until well after the 10th century (CE) and the conversion of the most northerly Europeans.

In 1582, scholars introduced the Gregorian calendar as they found that the vernal equinox and Easter did not correspond according to the system used by Church fathers.

Many adjustments or intercalations were made in the Julian calendar (Roman -style) time and the Gregorian period that are still required today despite our sophisticated atomic clock.  Leap seconds have to be introduced to keep our calendar in sync with the seasons.

• An overview of Civilization from an on-line course.    < help for those with little history background; a refresher for others.  NB It is not an authoritative enough source to cite from.
• Visit Religious Intolerance org for more about referring to people in various ways.
• Thinking about Judaism, Christianity and Islam at NYU    < good site for French-speaking students to learn English terminology, too.
• an Orthodox Jewish person's view of Christianity < an eye-opener, perhaps

• Whatever happened to Einstein's brain?