Three Shabbat Meals
We are required to eat three Shabbat meals, as a rabbinic (d'rabanan) enactment to enjoy Shabbat (oneg Shabbat). The first Shabbat meal must be at night and the remaining two must be during the day (the third meal must be eaten after halachic midday). Friday night dinner and the first meal on Saturday are preceded by kiddush. For the first two Shabbat meals, say ha'motzi over two complete loaves of bread, each of which is at least 1.3 fl. oz. in volume. For the third meal, the ideal is to use two complete loaves of bread, but the requirement of eating the third meal can also be fulfilled by eating any food other than salt or water.

Source of Saying Shabbat Kiddush

• Saying kiddush on Shabbat night is a commandment from the Torah (d'oraita).
• Saying kiddush on Saturday morning is a rabbinical (d'rabanan) enactment.

Note If you did not say Friday night kiddush, you must say that version of kiddush on Shabbat morning and it is then a requirement from the Torah (d'oraita). Do not begin with va'yechulu; instead, begin with borei pri ha'gafen and say the second blessing of kiddush.

Source of Kiddush Location
Saying kiddush at the place where you will eat your meal is a rabbinical (d'rabanan) enactment.

Shabbat Kiddush-Meal Quantities: Evening

• For evening kiddush, a minimum of 4 fl. oz. (119 ml) of wine must be blessed on and at least half must be drunk.
• For the evening meal, as on Shabbat lunch and all required Jewish festival meals, a minimum of 1.9 fl. oz. of bread must be eaten within four minutes.

Shabbat Kiddush-Meal Quantities: First Meal on Saturday
Shabbat day first meal has two separate eating requirements.  They may be combined (say/hear kiddush and start the main meal right away) but are often done separately (say/hear kiddush and then eat some mezonot; the main meal is eaten later in the day).
Note Since eating and drinking requirements on all morning kiddushes (both Shabbat and Jewish festivals) are d'rabanan, the required beverage amount for morning kiddush is only 3.3 fl. oz. (99 ml) instead of the d'oraita 4 fl. oz. (119 ml), which is required for kiddushes for Shabbat evening.
1) Morning kiddush requires a halachically legal “meal” with these elements:
      a) Blessing on a minimum of 3.3 fl. oz. (99 ml) of wine (or other beverage),
      b) Someone's drinking at least 2 fl. oz. of the beverage, followed by
      c) Eating at least 1.3 fl. oz. (39 ml, or 1/6 cup) of some type of mezonot (or bread) within four minutes.
Note If you drink at least 3.3 fl. oz. (99 ml) of wine within 30 seconds, you do not need to eat mezonot.
Note You do not need to drink the wine or other kiddush beverage to fulfill “establishing a meal.” You may hear kiddush and then simply eat the required amount of bread or mezonot. This applies to Shabbat or Jewish festivals, evening or morning.
The kiddush “meal” does not have to satiate.
Note If you have not fulfilled the requirements for kiddush, you may not eat other foods, such as fruit or fish at a kiddush.

2) The real meal (kovei'a se'uda) of Shabbat lunch requires eating at least 1.9 fl. oz. (56 ml) of bread (or matza during Passover!) within four minutes. It should include enough food to satiate.
Note You can simultaneously fulfill the requirement to “establish a meal” and to “eat a meal” by eating one (the same) piece of bread.
For details on fulfilling the first two meals' requirements, see Shabbat: Kiddush.

Shabbat: Eating a Meal Requirement: Third Meal
For details on fulfilling the third meal's requirements, see Shabbat: Third Meal (Se'uda Shlishit).

Jewish Festivals are listed in the Torah and are of two types: 

1. Three pilgrimage festivals (shalosh regalim):

• Passover,
• Shavuot, and
• Sukkot (including Shimini Atzeret).

These festivals were celebrated in ancient times by "appearing before God"--by bringing offerings to the Tabernacle or Temple.

2. High Holidays: 

• The Jewish New Year (Rosh Hashana—“Yom Teru'a” in the Torah), and the
• Day of Atonement (Yom Kippur).

 
Duration
Jewish holidays that were originally one day are now observed as follows:

• Rosh Hashana--2 days.
• Yom Kippur--1 day.
• Shavuot--1 day in Eretz Yisrael or 2 days elsewhere.
• Passover has festival days at the beginning and end of the holiday and intermediary days of lesser holiness, which are called chol ha'moed. In Eretz Yisrael, Passover lasts for 7 days in total and the first and last days are festival days. Outside of Eretz Yisrael, Passover lasts 8 days and has two festival days at the beginning and two at the end.
• Sukkot has festival days at the beginning and at the end and intermediary days of lesser holiness, which are called chol ha'moed. In Eretz Yisrael, Sukkot lasts for 8 days and the first and last days are festival days (the last day is Shimini Atzeret). Outside of Eretz Yisrael, Sukkot lasts for 9 days and the first two days and last days are festival days (the 8th day is Shimini Atzeret and the 9th day is Simchat Torah).

Character
Each holiday contributes its own character to Jewish life (Passover--the theme of freedom; Yom Kippur brings atonement, etc.). 

Celebrating
How to celebrate these holidays is detailed in our Oral Law and halacha books. Jewish festivals as practiced today are similar in holiness to Shabbat. As with Shabbat, the Jewish festival has candle lighting, kiddush at two meals, and havdala.   We eat our best food and wear our best clothing on Jewish festivals (we eat our next-best food and wear our next-best clothing on Shabbat!).
The main idea behind eating meals on Jewish festivals is joy (simcha), so you should drink wine and eat meat (only if you enjoy wine and meat).  There is no third meal on Jewish festivals since people used to eat two meals each day (adding a third meal on Shabbat was for enjoyment/oneg).
 
Melachot
Any activities or actions permitted on Shabbat are also permitted on the Jewish festivals. Actions that are forbidden on Shabbat are generally also forbidden on Jewish festivals, but there are some leniencies (only if the actions are needed for that festival day).
Examples

• Lighting from an existing flame,
• Cooking and baking for the Jewish festival day, and
• Carrying outside the eruv (hotza'a--transferring objects between domains).

 
Grama
Grama (indirectly causing an action) is permitted on Jewish festivals (but not on Shabbat). For example, you may advance or delay a timer that will make a light go on or off in the future (the timer must already be plugged in and operating from before sunset of the festival day).
Note For an action to be considered indirect based on time, there must be at least 2.5 seconds after the first action is done before the resulting action begins to happen.

Psik Reisha Dla Neicha Lei
Psik reisha dla neicha lei is forbidden on Jewish festivals, just as it is on Shabbat.

D'oraita Restrictions
D'oraita restrictions apply world-wide to:

• First and seventh days of Passover,
• First and eighth days of Sukkot,
• First day of Shavuot,
• Yom Kippur,
• First day of Rosh Hashana.

Note The same restrictions apply to all other Jewish festival days but are rabbinical.
 
Women
In general, women are not required to perform the positive, time-dependent commandments. Women and girls are not required to eat any Jewish festival meals except the Passover seder meal (but they are not allowed to fast on those days).

Introduction to Missed Amida/Tashlumim
If you accidentally miss any amida, you may make up for it (tashlumin)--unless you intentionally missed it.

Amida: Errors: Missed Amida/Tashlumin: Regular Days
Missed Ma'ariv Amida
If you accidentally did not say the amida for ma'ariv:

• Say the normal shacharit amida the next morning with the other men in the minyan.
• Say ashrei.
• When the leader begins his repetition of the amida, say the amida along with him, word for word, including kedusha.
• After saying ha'el ha'kadosh, finish your amida at your own pace.
• If you are not with a minyan, say ashrei and then repeat the shacharit amida.

Missed Shacharit Amida
If you accidentally did not say the amida for shacharit:

• Say the normal mincha amida with the other men in the minyan.
• Say ashrei.

• When the leader begins his repetition of the amida, say the amida along with him, word for word, including kedusha.
• After saying ha'el ha'kadosh, finish your amida at your own pace.
• If you are not with a minyan, say ashrei and then say the mincha amida a second time.

Missed Mincha Amida
If you accidentally did not say the amida for mincha:

• Say the normal ma'ariv amida with the other men in the minyan.
• Say ashrei.
• Say the ma'ariv amida a second time. Skip modim.
• If you are not with a minyan, say ashrei a second time and repeat the ma'ariv amida.

Note At the next prayer service, say whatever is the correct amida for that later prayer service, even if it is not the same amida that you missed.
If you miss mincha on Friday, say the ma'ariv service for Shabbat and repeat that amida again.
Note Once the time for the next amida has passed, you may not make up the missed amida.
Example
If you missed mincha on Thursday, you may only say tashlumin for mincha as long as you may still say ma'ariv, which is daybreak of Friday morning.

Amida: Errors: Missed Amida/Tashlumin: Shabbat/Jewish Festivals
Even if you forgot to say a prayer service on Shabbat and Jewish festivals, say the next prayer service amida and repeat THAT amida to make up (tashlumin) for the one you missed--even if it is no longer Shabbat or the Jewish festival.
Exception
There is no tashlumin for musaf. However, you may say musaf until sunset, even if you already said mincha.
Note If the time for mincha has arrived (½ hour after halachic midday), you must say mincha before saying musaf (but if you could join a mincha minyan later, you may say musaf now).
Situation
You miss Shabbat mincha.
What to Do
Say ata chonantanu in ma'ariv, but only for the first time you say the amida, not the second time (which is tashlumin).
Situation
You forget to say ma'ariv on Saturday night.
What to Do
Say ata chonantanu on Sunday morning in the second amida (which is tashlumin).

If Doubt about Whether You Said Amida
If you are not certain whether you said an amida:

• On a weekday, assume that you did not say the amida and say it anyway.  Intend that:
  • If you forgot the previous amida, this makes up for it, and
  • If you did say the previous amida, the second one is a nedava (free-will “offering”).
• On Shabbat and Jewish festivals, do not say the amida twice as tashlumin.

            Reason You may not say a voluntary prayer service (nedava) on these days.
Men who intentionally delayed saying shacharit past the fourth halachic hour of the day still say that amida until midday but if they did not say it by midday, they may not say tashlumin. See Minyan: Keeping Pace: Shacharit Minyan.

Who Is a Mourner

A mourner is defined in halacha as someone mourning during the 12-month mourning period for parents or the 30-day mourning period for the other five relatives (spouse, brother, sister, son, daughter). After 30 days, one is no longer a mourner for anyone but one's parents.

Mourners' Restrictions

If the mourner goes about business as usual, it may show he or she doesn't care about the close relative who died. The mourner should ideally not want to do these things. The mourner honors the dead person by refraining from pampering him/herself and refraining from going about his or her life as usual.

Public Meals

A mourner may not attend a public meal for any purpose. For example, if the mourner attends a lecture or Torah class at which food is being served, he or she may not eat the food. This only applies to sit-down meals; snacking is permitted.

Siyum/Brit/Bar Mitzva

After 30 days after a parent's burial, a mourner may:

• Attend a siyum or bar mitzva and eat there.
• Attend a brit but not eat there.

Note If there is music (live or recorded), the mourner must leave.

Weddings

A mourner may not eat at a wedding and may not even be in the wedding hall after the ceremony took. The mourner may also not hear the music at a wedding.

Exceptions

• If the mourner is the parent of someone getting married, the mourner can fully participate in the wedding.
• If the mourner is the bride or groom, he or she must normally wait to get married until after shloshim/30 days.

Note If it is after shiva, but still during shloshim, consult a rabbi.

Kiddush and Shabbat or Festival Meals

A mourner may not publicly (noticeably) mourn on Shabbat or festivals so he or she may attend Shabbat or festival meals and kiddushes if he or she would be expected to attend. If the mourner always or routinely invites some person or a lot of different people on Shabbat or festivals, it is still permitted. If the mourner does not routinely invite some person or a lot of different people to a Shabbat or festival meal, then he or she may not, for his or her own enjoyment, invite guests for meals. However, the mourner is permitted to do so for other purposes (for the benefit of the invited person or people), such as kiruv or hachnasat orchim. There is no limit to how many guests the mourner may host.

The mourner may attend or host a sheva brachot in his/her home.

A mourner should not be invited to meals, even for Shabbat or festivals; but if he/she was invited, he/she may go.

Holidays

A mourner does eat at a Purim or Jewish festival seuda, since there is no mourning on Purim nor on any festival (except Chanuka).

You may dilute sunscreen before Jewish festivals with water or alcohol, but some sunscreens may not become more fluid even with added water or alcohol.
 

You may not send a shipment--such as Fedex or another express delivery service--to arrive on Jewish festivals.  However, you may tell the shipper that it is OK with you if it is delivered at night after the festival.
 

Here are the d'oraita Jewish festivals:

• First day of Sukkot, Passover, and Shavuot
• Seventh day of Passover
• Shmini Atzeret (8^th day of Sukkot)
• Both days of Rosh Hashana.

On these days, you:

• MUST take medicine whenever there is any question of a life-threatening disease or condition.
• MAY take medicine for a condition that affects the entire body (fever, weakness, etc.). Consult a rabbi if possible.
  Exception You may not smear substances on skin UNLESS the fever is life-threatening, in which case even smearing is permitted.
• MAY use some medicines if only part of your body is affected by a non-life-threatening disease--consult a rabbi.

You may not cut floss on Jewish festivals, so it is best to cut the floss before the festival starts. 

You may directly ask a non-Jew to turn on a stove or oven for you.
NOTE Be careful about bishul akum problems if a non-Jew will then be cooking food for Jews on that stove or oven.

You may stretch on Jewish festivals (and Shabbat) to make yourself more comfortable but not if it appears that you are doing it as exercise for health.

You may not cut a tag off clothes on Jewish festivals.

You may wipe a stain off of your face or hands onto a cloth or piece of paper if you do it to clean your face or hands on Jewish festivals (and Shabbat), but not if you want to color the cloth or paper.

On Jewish festivals (and Shabbat), you may dangle your feet or legs into a pool (or other body) of water up to whatever garment you are wearing. However, you may not let the garment get wet.